Log OTP evaluation and redaction events upon getting SMS messages

These metrics will track performance, as well as guage frequency of
suppressed messages

Bug: 351976749
Test: atest MetricsCollectorTest PersistAtomsStorageTest
Flag: com.android.internal.telephony.flags.redact_otp_sms
Change-Id: Ic5dc6cd4cf840a5a5e746eb49ba6857a3790c9f5