Clear identity when checking strongauth flags

Bug: 161557889
Bug: 161566755

Test: atest FingerprintManagerTest
Test: AccessibilityFingerprintGestureTest#testGestureDetectionListener_whenAuthenticationStartsAndStops_calledBack
Change-Id: Icb273fc0cf2ce1891550130539c0b2e6e788b533
1 file changed