Keyguard: Don't lock when phone process crashes

Fixed an issue where the keyguard locked in response to the
phone process crashing. Since that's not avoidable for the
moment, don't treat unknown sim states as absent.

Bug: 78060670
Test: adb shell kill `pid com.android.phone`; verify that the phone did not lock
Change-Id: Ic5aa51d3b0521740b828d934c6653f8d5ae6380a