Fix #19069 - IsWebstoreUpdateUrl should return true for kChromeWebstoreUpdateURL even when component-updater switch is set

[jumde]

Resolves brave/brave-browser#19069

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:

1. Open Brave Browser with a clean profile and verify that all components are installed correctly.
2. Navigate to: https://chrome.google.com/webstore/detail/google-translate/aapbdbdomjkkjkaonfhkkikfgjllcleb
3. Add to Brave
4. Navigate to brave://extensions/
5. Click details
6. Verify the source says Web Extensions Store

[kjozwiak]

Verification PASSED on Win 11 x64 using the following build:

Brave | 1.34.23 Chromium: 96.0.4664.45 (Official Build) nightly (64-bit)
-- | --
Revision | 76e4c1bb2ab4671b8beba3444e61c0f17584b2fc-refs/branch-heads/4664@{#947}
OS | Windows 11 Version 21H2 (Build 22000.318)

• verified the STR/Cases outlined via Fix #19069 - IsWebstoreUpdateUrl should return true for kChromeWebstoreUpdateURL even when component-updater switch is set #10781 (comment)
• ensured that components were being installed on a new profile & updated correctly under brave://components
• ensured that Source displays Web Extensions Store under brave://extensions

Example	Example