Fixed Disabled ads tracking option is reverted after reloading (uplift to 1.15.x)

[simonhong]

Uplift of #6693
Resolves brave/brave-browser#11585

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[kjozwiak]

test-browser failed on macOS due to RewardsContributionBrowserTest.MultipleTipsProduceMultipleFeesWithVerifiedWallet failing as per https://ci.brave.com/job/pr-brave-browser-pr6693_uplift_1.15.x-macos/1/flowGraphTable/. However, this is a known intermittent failure that doesn't block uplift.

21:44:56  [  FAILED  ] RewardsContributionBrowserTest.MultipleTipsProduceMultipleFeesWithVerifiedWallet, where TypeParam =  and GetParam() =  (1385 ms)
21:44:56  [620/620] RewardsContributionBrowserTest.MultipleTipsProduceMultipleFeesWithVerifiedWallet (1596 ms)
21:44:56  1 test failed:
21:44:56      RewardsContributionBrowserTest.MultipleTipsProduceMultipleFeesWithVerifiedWallet (../../brave/components/brave_rewards/browser/test/rewards_contribution_browsertest.cc:465)

[kjozwiak]

Uplift into 1.15.x approved after deliberating with @brave/uplift-approvers. QA has verified the PR on Nightly as per #6693 (comment).