Should reset mDismissKeyguard on keyguard secure change

If user sets a non-secure lock screen, launch an activity which
appends window flag FLAG_DISMISS_KEYGUARD, then insert a PIN lock
SIM card, activity window will become black screen.

This is because mDismissKeyguard keeps on DISMISS_KEYGUARD_CONTINUE
when keyguard secure changes from non-secure to secure like in the
insert PIN lock SIM card case. If mDismissKeyguard is
DISMISS_KEYGUARD_CONTINUE and keyguard is secure, there is no chance
to launch keyguard unlock window anymore.

This patch handles the use case that to reset mDismissKeyguard to a
new cycle from DISMISS_KEYGUARD_START to DISMISS_KEYGUARD_CONTINUE
again once keyguard secure state change suddenly to let keyguard
window has chance to be launched.

https://code.google.com/p/android/issues/detail?id=78806



Change-Id: I0d4fd0b9bdf7d0a39f35427bfd4e1b928d9bca6b
Signed-off-by: tingna_sung <tingna_sung@htc.com>

Conflicts:
	policy/src/com/android/internal/policy/impl/PhoneWindowManager.java