Fixes follow up to #11057: Implement client ads pacing mechanism - 1.14.x

[tmancey]

Uplift of #6614
Resolves brave/brave-browser#11643

• 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.

[kjozwiak]

test-browser failed on Win x64 due to GreaselionServiceTest.ScriptInjectionWithPrecondition failing as per https://ci.brave.com/job/pr-brave-browser-issues-11643-1.14.x-windows/2/execution/node/216/log/. However, this is a known intermittent issue and doesn't block uplift.

11:47:12  [  FAILED  ] GreaselionServiceTest.ScriptInjectionWithPrecondition, where TypeParam =  and GetParam() =  (2888 ms)
11:47:12  
11:47:12  [605/605] GreaselionServiceTest.ScriptInjectionWithPrecondition (3060 ms)
11:47:12  1 test failed:
11:47:12      GreaselionServiceTest.ScriptInjectionWithPrecondition (../../brave/browser/greaselion/greaselion_browsertest.cc:265)

Restarting Win x64 via https://ci.brave.com/job/pr-brave-browser-issues-11643-1.14.x-windows/3/ using WIPE_WORKSPACE due to test-install failing as per https://ci.brave.com/job/pr-brave-browser-issues-11643-1.14.x-windows/2/execution/node/240/log/.

12:06:06  powershell.exe : Start-Process : This command cannot be run due to the error: The system cannot find the file specified.
12:06:06  At C:\14.x@tmp\durable-290ab87c\powershellWrapper.ps1:3 char:1
12:06:06  + & powershell -NoProfile -NonInteractive -ExecutionPolicy Bypass -Comm ...
12:06:06  + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
12:06:06      + CategoryInfo          : NotSpecified: (Start-Process :...file specified.:String) [], RemoteException
12:06:06      + FullyQualifiedErrorId : NativeCommandError
12:06:06   
12:06:06  At C:\14.x@tmp\durable-290ab87c\powershellScript.ps1:10 char:17
12:06:06  + ...             Start-Process "C:\Users\Administrator\AppData\Local\Brave ...
12:06:06  +                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
12:06:06      + CategoryInfo          : InvalidOperation: (:) [Start-Process], InvalidOperationException
12:06:06      + FullyQualifiedErrorId : InvalidOperationException,Microsoft.PowerShell.Commands.StartProcessCommand

Restarted macOS via https://ci.brave.com/job/pr-brave-browser-issues-11643-1.14.x-macos/4/ due to build failing as per https://ci.brave.com/job/pr-brave-browser-issues-11643-1.14.x-macos/2/execution/node/174/log/.

10:40:33  FAILED: obj/brave/components/brave_ads/browser/browser/ads_tab_helper.o 

[kjozwiak]

Uplift into 1.14.x approved after deliberating with @brave/uplift-approvers. QA has also verified the PR on Nightly as per #6614 (comment).