No Bug: Hide Rewards User Wallets unless compiler flag is used

[kylehickinson]

To be reverted in a future PR

For QA (cc @srirambv @kjozwiak): This just hides the button, the underlying wallet may still exist in your build, and you will need to reset rewards/delete & reinstall the build

Submitter Checklist:

• Unit Tests are updated to cover new or changed functionality
• User-facing strings use NSLocalizableString()

Test Plan:

• Verify without the compiler flag added when compiling that user wallets is not available in the build

Reviewer Checklist:

• Issues include necessary QA labels:
  • QA/(Yes|No)
  • release-notes/(include|exclude)
  • bug / enhancement
• Necessary security reviews have taken place.
• Adequate unit test coverage exists to prevent regressions.
• Adequate test plan exists for QA to validate (if applicable).
• Issue is assigned to a milestone (should happen at merge time).

[kylehickinson]

Wait to merge until I can rebase on #2204

[kylehickinson]

Failed with same test errors, merging anyways