Fixes Brave Ads intermittently crashes when opening a new tab - 1.12.x

[tmancey]

Uplift of #6304
Resolves brave/brave-browser#9393

• You have checked CI and the builds, lint, and tests all pass or are not related to your PR.
• You have tested your change on Nightly.
• The PR milestones match the branch they are landing to.

After you merge:

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

[tmancey]

CI failed for known Brave Rewards browser test issue

[kjozwiak]

Currently PR/Blocked due to not being able to QA #6305 until #6248 has been fixed on Nightly.

[LaurenWags]

The following platforms failed CI and are being restarted:

• Android failed --> https://ci.brave.com/job/pr-brave-browser-issues-9393-1.12.x/1/execution/node/444/log/
• Linux failed --> https://ci.brave.com/job/pr-brave-browser-issues-9393-1.12.x/1/execution/node/413/log/
• macOS failed --> https://ci.brave.com/job/pr-brave-browser-issues-9393-1.12.x/1/execution/node/322/log/
• Win x64 failed --> https://ci.brave.com/job/pr-brave-browser-issues-9393-1.12.x/1/execution/node/540/log/

[kjozwiak]

Looks like it failed at the same exact spot on all the platforms other than iOS. Looks like it's failing the build process due to the following failure:

16:31:17  FAILED: obj/brave/components/brave_ads/browser/browser/ads_service_impl.o

@tmancey mind taking a look when you're around? Keeping the PR/Blocked for now till the above is resolved.

[tmancey]

@kjozwiak Issue resolved and builds restarted

[kjozwiak]

Uplift into 1.12.x approved after deliberating with @brave/uplift-approvers. QA has verified the PR on Nightly as per #6304 (comment).