Rely on isKeyguardDismissible for insecure camera launch

This also matches the logic in CameraGestureHelper which
relies solely on the keyguard being dismissible. This should
help with inconsistencies in KeyguardState.

Test: atest FromAodTransitionInteractorTest
Fixes: 339851684
Flag: EXEMPT
Change-Id: Iafd6aa2c32e3ff2833a5d66c00b31a150a63fc44