Gitlab v7.10.5 CE omnibus installation : Failed due to postgres error

root@ip-10-0-2-159:/var/log/gitlab/postgresql# gitlab-rake db:create db:migrate
PG::Error: ERROR: permission denied to create database
: CREATE DATABASE “gitlabhq_production” ENCODING = ‘unicode’
/opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/activerecord-4.1.9/lib/active_record/connection_adapters/postgresql/database_statements.rb:128:in exec' /opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/activerecord-4.1.9/lib/active_record/connection_adapters/postgresql/database_statements.rb:128:in block in execute’
/opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/activerecord-4.1.9/lib/active_record/connection_adapters/abstract_adapter.rb:373:in block in log' /opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/activesupport-4.1.9/lib/active_support/notifications/instrumenter.rb:20:in instrument’
/opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/activerecord-4.1.9/lib/active_record/connection_adapters/abstract_adapter.rb:367:in log' /opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/activerecord-4.1.9/lib/active_record/connection_adapters/postgresql/database_statements.rb:127:in execute’
/opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/activerecord-4.1.9/lib/active_record/connection_adapters/postgresql/schema_statements.rb:80:in create_database' /opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/activerecord-4.1.9/lib/active_record/tasks/postgresql_database_tasks.rb:17:in create’
/opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/activerecord-4.1.9/lib/active_record/tasks/database_tasks.rb:88:in create' /opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/activerecord-4.1.9/lib/active_record/tasks/database_tasks.rb:102:in block in create_current’
/opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/activerecord-4.1.9/lib/active_record/tasks/database_tasks.rb:223:in block in each_current_configuration' /opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/activerecord-4.1.9/lib/active_record/tasks/database_tasks.rb:222:in each’
/opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/activerecord-4.1.9/lib/active_record/tasks/database_tasks.rb:222:in each_current_configuration' /opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/activerecord-4.1.9/lib/active_record/tasks/database_tasks.rb:101:in create_current’
/opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/activerecord-4.1.9/lib/active_record/railties/databases.rake:17:in block (2 levels) in <top (required)>' /opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/rake-10.4.2/lib/rake/task.rb:240:in call’
/opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/rake-10.4.2/lib/rake/task.rb:240:in block in execute' /opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/rake-10.4.2/lib/rake/task.rb:235:in each’
/opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/rake-10.4.2/lib/rake/task.rb:235:in execute' /opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/rake-10.4.2/lib/rake/task.rb:179:in block in invoke_with_call_chain’
/opt/gitlab/embedded/lib/ruby/2.1.0/monitor.rb:211:in mon_synchronize' /opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/rake-10.4.2/lib/rake/task.rb:172:in invoke_with_call_chain’
/opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/rake-10.4.2/lib/rake/task.rb:165:in invoke' /opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/rake-10.4.2/lib/rake/application.rb:150:in invoke_task’
/opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/rake-10.4.2/lib/rake/application.rb:106:in block (2 levels) in top_level' /opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/rake-10.4.2/lib/rake/application.rb:106:in each’
/opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/rake-10.4.2/lib/rake/application.rb:106:in block in top_level' /opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/rake-10.4.2/lib/rake/application.rb:115:in run_with_threads’
/opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/rake-10.4.2/lib/rake/application.rb:100:in top_level' /opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/rake-10.4.2/lib/rake/application.rb:78:in block in run’
/opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/rake-10.4.2/lib/rake/application.rb:176:in standard_exception_handling' /opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/rake-10.4.2/lib/rake/application.rb:75:in run’
/opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/rake-10.4.2/bin/rake:33:in <top (required)>' /opt/gitlab/embedded/service/gem/ruby/2.1.0/bin/rake:23:in load’
/opt/gitlab/embedded/service/gem/ruby/2.1.0/bin/rake:23:in `’
Couldn’t create database for {“adapter”=>“postgresql”, “encoding”=>“unicode”, “database”=>“gitlabhq_production”, “pool”=>10, “username”=>“gitlab”, “password”=>nil, “host”=>nil, “port”=>5432, “socket”=>nil}

Error in the postgres logs
2017-12-05_07:18:21.03479 received TERM from runit, sending INT instead to force quit connections
2017-12-05_07:18:21.03631 LOG: received fast shutdown request
2017-12-05_07:18:21.03631 LOG: aborting any active transactions
2017-12-05_07:18:21.03712 LOG: autovacuum launcher shutting down
2017-12-05_07:18:21.03724 LOG: shutting down
2017-12-05_07:18:21.05058 LOG: database system is shut down
2017-12-05_07:18:21.11366 LOG: database system was shut down at 2017-12-05 07:18:21 GMT
2017-12-05_07:18:21.12457 LOG: database system is ready to accept connections
2017-12-05_07:18:21.12514 LOG: autovacuum launcher started
2017-12-05_07:18:21.49848 received TERM from runit, sending INT instead to force quit connections
2017-12-05_07:18:21.49990 LOG: received fast shutdown request
2017-12-05_07:18:21.49991 LOG: aborting any active transactions
2017-12-05_07:18:21.50058 LOG: autovacuum launcher shutting down
2017-12-05_07:18:21.50068 LOG: shutting down
2017-12-05_07:18:21.51422 LOG: database system is shut down
2017-12-05_07:18:22.58200 LOG: database system was shut down at 2017-12-05 07:18:21 GMT
2017-12-05_07:18:22.59298 LOG: database system is ready to accept connections
2017-12-05_07:18:22.59344 LOG: autovacuum launcher started
2017-12-05_07:20:07.58521 ERROR: permission denied to create database
2017-12-05_07:20:07.58523 STATEMENT: CREATE DATABASE “gitlabhq_production” ENCODING = ‘unicode’
2017-12-05_10:56:49.09879 ERROR: permission denied to create database
2017-12-05_10:56:49.09882 STATEMENT: CREATE DATABASE “gitlabhq_production” ENCODING = ‘unicode’
2017-12-05_11:15:29.55301 ERROR: permission denied to create database
2017-12-05_11:15:29.55303 STATEMENT: CREATE DATABASE “gitlabhq_production” ENCODING = ‘unicode’

Fresh installation, we need to convert non-omnibus installation(mysql) to omnibus installation(postgresql)
Doc followed :https://docs.gitlab.com/ee/update/mysql_to_postgresql.html#converting-a-gitlab-backup-file-from-mysql-to-postgres

Please help with the same