fixes ads on yt and gets rid of csp error (uplift to 1.22.x)

[brave-builds]

Uplift of #8071
Resolves brave/brave-browser#14359

Pre-approval checklist:

• You have tested your change on Nightly.
• This contains text which needs to be translated.
  • There are more than 7 days before the release.
  • I've notified folks in #l10n on Slack that translations are needed.
• The PR milestones match the branch they are landing to.

Pre-merge checklist:

• You have checked CI and the builds, lint, and tests all pass or are not related to your PR.

Post-merge checklist:

• The associated issue milestone is set to the smallest version that the changes is landed on.

[kjozwiak]

@SergeyZhukovsky looks like post-init failed on lint a per https://ci.brave.com/job/pr-brave-browser-pr8071_yt_ads_problem_1.22.x-post-init/1/execution/node/147/log/. Mind taking a look?

11:25:15  Running cpplint...
11:25:15  chromium_src/chrome/common/chrome_isolated_world_ids.h:6:  #ifndef header guard has wrong style, please use: BRAVE_CHROMIUM_SRC_CHROME_COMMON_CHROME_ISOLATED_WORLD_IDS_H_  [build/header_guard] [5]
11:25:15  chromium_src/chrome/common/chrome_isolated_world_ids.h:16:  #endif line should be "#endif  // BRAVE_CHROMIUM_SRC_CHROME_COMMON_CHROME_ISOLATED_WORLD_IDS_H_"  [build/header_guard] [5]

Restarting macOS as it looks like both test-browser & test-unit never completed.

[kjozwiak]

Uplift into 1.22.x approved after deliberating with @brave/uplift-approvers. QA has verified the PR on Nightly as per #8071 (comment). The lint issues mentioned via #8077 (comment) will be addressed in https://github.com/brave/brave-core/pull/8081/files#diff-43908f4c88195ffd975034fbc1aafb83cd7929f33802f13a05ebfb2a454a99f2L6 which will also be uplifted into 1.22.x & 1.21.x.