Automatically fix bad FRP block written by Android 14 Beta 2

Make LockSettingsService automatically fix the FRP persistent data block
if it is in the "bad" format written by Android 14 Beta 2 which Android
13 can't understand.

Previously, the FRP persistent data block only got fixed if the user
happened to set, change, or clear their lockscreen credential.  I.e.,
the code that wrote the FRP block was fixed, but there wasn't anything
that made the FRP block be written when not otherwise needed.

Bug: 276780938
Test: atest com.android.server.locksettings
Test: Installed udc-beta2 and added Google account and PIN.  Upgraded to
      build with this CL, without wiping.  Then downgraded to tm-qpr2,
      with wiping (but not through Settings).  Verified that the FRP
      challenge is presented in the Setup Wizard and can be passed.
      Without this CL, the bad FRP block would not have been fixed.
Change-Id: Ifbe8646af679118a1f6bb696f1ede9a359cffdc2