Work profile first run updates

- Show until the user dismisses it.
- Fetch the app icon based upon config ComponentName.
- Fetch the app name based upon config.
- Extract relevant logic to WorkProfileMessageController
- Some no-op cleanups in SaveIMageInBackgroundTask to prevent sysui
  studio from complaining.

Flag: The calls into the new message controller are protected by
      SCREENSHOT_WORK_PROFILE_POLICY (in teamfood).
Bug: 254245929
Test: atest WorkProfileMessageControllerTest
Test: Manually testing dismissal and UI.
Change-Id: I943303992fdc2caeba76a06f88c1b91419d02be8