[Android] Added ability to set tes variations server prior to first t…

[samartnik]

…ime run

Resolves brave/brave-browser#18577

Submitter Checklist:

• I confirm that no security/privacy review is needed, or that I have requested one
• There is a ticket for my issue
• Used Github auto-closing keywords in the PR description above
• Wrote a good PR/commit description
• Added appropriate labels (QA/Yes or QA/No; release-notes/include or release-notes/exclude; OS/...) to the associated issue
• Checked the PR locally: npm run test -- brave_browser_tests, npm run test -- brave_unit_tests, npm run lint, npm run gn_check, npm run tslint
• Ran git rebase master (if needed)

Reviewer Checklist:

• A security review is not needed, or a link to one is included in the PR description
• New files have MPL-2.0 license header
• Adequate test coverage exists to prevent regressions
• Major classes, functions and non-trivial code blocks are well-commented
• Changes in component dependencies are properly reflected in gn
• Code follows the style guide
• Test plan is specified in PR before merging

After-merge Checklist:

• The associated issue milestone is set to the smallest version that the
  changes has landed on
• All relevant documentation has been updated, for instance:
  • https://github.com/brave/brave-browser/wiki/Deviations-from-Chromium-(features-we-disable-or-remove)
  • https://github.com/brave/brave-browser/wiki/Proxy-redirected-URLs
  • https://github.com/brave/brave-browser/wiki/Fingerprinting-Protections
  • https://github.com/brave/brave-browser/wiki/Brave%E2%80%99s-Use-of-Referral-Codes
  • https://github.com/brave/brave-browser/wiki/Custom-Headers
  • https://github.com/brave/brave-browser/wiki/Web-Compatibility-Exceptions-in-Brave
  • https://github.com/brave/brave-browser/wiki/QA-Guide
  • https://github.com/brave/brave-browser/wiki/P3A

Test Plan:

[SergeyZhukovsky]

++

[AlexeyBarabash]

👍

[kjozwiak]

Verification PASSED using Samsung S10+ on Android 11 using the following build:

1.32.60 Chromium: 95.0.4638.40

Terminal commands used:

Opens an adb shell and creates a filed named brave-test-variations-server-url under /data/local/tmp with the value specified:

• adb shell "echo 'https://variations.bravesoftware.com/seed' > /data/local/tmp/brave-test-variations-server-url"

Removes the file from /data/local/tmp:

• adb shell "rm /data/local/tmp/brave-test-variations-server-url"

Check if the file brave-test-variations-server-url still exsists:

• adb shell "cat /data/local/tmp/brave-test-variations-server-url"

Test Case #1 - using https://variations.bravesoftware.com/seed

Using the commands mentioned above, started Brave and ensured:

• variations/seed wasn't appearing under brave://version on the first launch
• restarted Brave and ensured that the seed from https://variations.bravesoftware.com/seed were listed under brave://version

First Launch	Second Launch

Test Case #2 - using https://no-thanks.invalid

Using the commands mentioned above, started Brave and ensured:

• variations/seed wasn't appearing under brave://version on the first launch
• restarted Brave and ensured no variations/seeds were listed under brave://version due to using https://no-thanks.invalid

First Launch	Second Launch