Improve spec for Gitlab::Ci::Status::Pipeline::Factory

Closes #52280

See merge request gitlab-org/gitlab-ce!22247

Enable some frozen string in lib/gitlab

See merge request gitlab-org/gitlab-ce!22304

Resolve "Show canary / no-canary in the performance bar"

Closes #52421

See merge request gitlab-org/gitlab-ce!22222

Only display merge commit SHA when it exists

Closes #48889

See merge request gitlab-org/gitlab-ce!22022

Update Android.gitlab-ci.yml for current stable SDK

See merge request gitlab-org/gitlab-ce!22336

Docs: Link to DeclarativePolicy framework from development guide

See merge request gitlab-org/gitlab-ce!22348

Docs: Fixing some bad links

See merge request gitlab-org/gitlab-ce!22287

Fix duplicated key in license management job gitlab-org/gitlab-ce#52609

Closes #52609

See merge request gitlab-org/gitlab-ce!22311

Enable frozen string for the following files:

* lib/gitlab/auth/**/*.rb
* lib/gitlab/badge/**/*.rb
* lib/gitlab/bare_repository_import/**/*.rb
* lib/gitlab/bitbucket_import/**/*.rb
* lib/gitlab/bitbucket_server_import/**/*.rb
* lib/gitlab/cache/**/*.rb
* lib/gitlab/checks/**/*.rb

Partially addresses #47424.

Fix rubocop complaining about unicorn.rb

See merge request gitlab-org/gitlab-ce!22332

Update merge request diff navigation docs

See merge request gitlab-org/gitlab-ce!22275

Drop support for Go 1.9 in GitLab 11.4

Closes #51982

See merge request gitlab-org/gitlab-ce!22324

Updates the check for started in job header

See merge request gitlab-org/gitlab-ce!22329

Add stage name in job.json response

Closes #52618

See merge request gitlab-org/gitlab-ce!22317

The function that was checking if the job was started or not
was expecting a boolean, however it was receiving a null.
During the refactor the condition was changed, causing the function
to break with null

This commit fixes the check

Fix the event API docs

Closes #52512

See merge request gitlab-org/gitlab-ce!22320

Backport CE changes for Ops Dashboard in EE

See merge request gitlab-org/gitlab-ce!22136

Updates gitlab-svg dependency

See merge request gitlab-org/gitlab-ce!22299

Update GitLab Pages to v1.2.1

See merge request gitlab-org/gitlab-ce!22318

If the request came from a canary host, show this in the performance bar
by:

1. Adding a bird emoji.
2. Colouring the hostname yellow.

Hide job sidebar on mobile

Closes #52608

See merge request gitlab-org/gitlab-ce!22314

Resolve "Make file browser hidden by default for mobile screens" and improve layout in small screens too

Closes #52361

See merge request gitlab-org/gitlab-ce!22273

This commit adds back `js-` classes needed to
automatically collapse the sidebar on resize.

Specification change: Fix asciidoctor block context.

See merge request gitlab-org/gitlab-ce!22280

Fix broken file name navigation on MRs

Closes #50185

See merge request gitlab-org/gitlab-ce!22109