Strict autoplay blocking

[darkdh]

Resolves brave/brave-browser#10811

This PR enforce autoplay blocking by setting policy to kUserGestureRequired and clear user activation(this is required for navigation and reloading) when autoplay setting is blocked. Also brings back autoplay blocked indicator.
The test is updated so that we can catch autoplay is not blocked in the future

Submitter Checklist:

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Verified that these changes build without errors on
  • Android
  • iOS
  • Linux
  • macOS
  • Windows
• Verified that these changes pass automated tests (unit, browser, security tests) on
  • iOS
  • Linux
  • macOS
  • Windows
• Verified that all lint errors/warnings are resolved (npm run lint, npm run gn_check)
• Ran git rebase master (if needed).
• Ran git rebase -i to squash commits (if needed).
• Tagged reviewers and labelled the pull request as needed.
• Requested a security/privacy review as needed.
• Added appropriate QA labels (QA/Yes or QA/No) to the associated issue
• Added appropriate release note labels (release-notes/include or release-notes/exclude) to the associated issue
• Public documentation has been updated as necessary. 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-issues-with-tracking-protection
  • https://github.com/brave/brave-browser/wiki/QA-Guide

Test Plan:

1. Go to youtube.com
2. Set autoplay to blocked (globally or site specifically)
3. Click any videos
4. It should not autoplay and there should be a autoplay blocked indicator on url bar
5. Click the video to play, it can be played
6. Refresh the page, it still should not autoplay
7. Navigate to other videos, it should not autoplay

Reviewer Checklist:

• New files have MPL-2.0 license header.
• Request a security/privacy review as needed.
• Adequate test coverage exists to prevent regressions
• Verify test plan is specified in PR before merging to source

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.

[bbondy]

Thanks for the tests

[mkarolin]

chromium_src/patches LGTM

[darkdh]

known issues
brave/brave-browser#12295

19:47:32  1 test failed:
19:47:32      RewardsContributionBrowserTest.RecurringTipForUnverifiedPublisher (../../brave/components/brave_rewards/browser/test/rewards_contribution_browsertest.cc:327)

https://ci.brave.com/job/pr-brave-browser-autoplay-block-windows/5/execution/node/236/log/