Override SafetyEvents

Sources may call setSafetySourceData with an incorrect/unexpected
SafetyEvent. One case we particularly care about is where a source has
successfully resolved an action, but sends SOURCE_STATE_UPDATED rather
than ACTION_SUCCEEDED - Phonesky/GPP is known to do this.

This CL adds a helper function ("fix") to optionally replace incoming
SafetyEvents when a certain heuristic says to do so.

Bug: 283780918
Test: SafetyCenterNotificationTest
Relnote: N/A
Change-Id: I29d50534bf54d29e4793bab2dec2eee2b7a24635