Updates settings page data when re-enabling rewards

[NejcZdovc]

Resolves brave/brave-browser#2892

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
  • Windows
  • macOS
  • Linux
• Verified that these changes pass automated tests (npm test brave_unit_tests && npm test brave_browser_tests) on
  • Windows
  • macOS
  • Linux
• Ran git rebase master (if needed).
• Ran git rebase -i to squash commits (if needed).
• Tagged reviewers and labelled the pull request as needed.
• Request a security/privacy review as needed.
• Add appropriate QA labels (QA/Yes or QA/No) to include the closed issue in milestone

Test Plan:

• Clean profile
• Run Brave with flag --rewards=staging=true,reconcile-interval=2
• Enable rewards brave://rewards and claim the grant
• Open kjozwiakstaging.github.io in a new tab and stay on it for 10s to add it to a-c table
• Disable rewards
• Wait till the reconcile-interval is passed (2 minutes)
• Enable rewards
• Make sure that ac table is cleared

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

[ryanml]

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