Update isSecureCameraActive flow to be false after unlock.

The current implementation of `KeyguardInteractor.isSecureCameraActive`
correctly emits `false` when secure camera is closed and the user goes
back to lockscreen or primary bouncer. But, the flow then incorrectly
emits `true` once the device is unlocked. This is because
`isKeyguardVisible` and `isPrimaryBouncerShowing` are both false and the
last camera launch event is still POWER_DOUBLE_TAP.

This CL updates the flow to still emit `false` even after the device is
unlocked by making sure that the keyguard becoming visible or the
primary bouncer showing correctly reset the flow value.

Fixes: 373700726
Bug: 364360986
Flag: EXEMPT bugfix

New tests:
Test: Launch secure camera over lockscreen, then go back to lockscreen,
then unlock the device -> verify flow emits `false`
Test: Launch secure camera over lockscreen, then go back to lockscreen,
then launch the Home shortcut from lockscreen -> verify flow emits
`false`
Test: atest KeyguardInteractorTest

Tests that ensure face auth hasn't regressed:
Test: Have face auth running on lock screen, then launch secure camera
-> verify face auth stops immediately (circle disappears without
animation), verify front camera in camera app works without delay
Test: Launch secure camera over lockscreen, then tap on locked gallery
icon -> verify alternate bouncer shows, face auth runs
Test: Launch secure camera over lockscreen, then tap on locked gallery
icon, then swipe up to go to primary bouncer -> verify face auth runs

Change-Id: I6bd5c7e43e3662f6dc8c49f3ca132eb69178cfcb