Fix Play integrity API check and cache updates

As explained at https://protonaosp.org/developers/details/safetynet
keeping the fingerprint fixed might lead to Android not updating some of
its caches after OS upgrades.
Using that approach of only patching the fingerprint when required also
makes the device pass `MEETS_BASIC_INTEGRITY` using the "Play integrity API"
in addition to passing SafetyNet.

Change-Id: I734552491f7e1d826cf27b96cbcacf91a54c16f9