Use VerifyCredentialResponse#isMatched() instead of comparing response code

The large number of callers of
VerifyCredentialResponse#getResponseCode() makes it hard to see in code
search how the response codes are being used.  However, most of them
just check for RESPONSE_OK, and there's already a method for that:
isMatched().  Use that instead.  No functional change.

Bug: 423038471
Test: atest FrameworksServicesTests:com.android.server.locksettings
Flag: EXEMPT refactor
Change-Id: Iaf4be81afafc3d7a67faaf788424ebbe8ef35194