Fix 5326463: rework sim state handling in lockscreen

Previously it was possible to get an inconsistent state because there
were two paths that updated the lock screen sim state.  This reworks
the data flow to ensure the same path is always used to update the state.

KeyguardUpdateMonitor now correctly updates the entire state of the callee
whenever a new callback is registered.

In addition, KeyguardUpdateMonitor now caches the phone state in order
to avoid a round-trip binder call in updateEmergencyCallButtonState().
This avoids a condition that could make lockscreen unresponsive while
updating the emergency call button state.

KeyguardStatusViewManager also ensures the TransportControlView is
hidden when created to ensure we don't inappropriately update the carrier
line while waiting for the first callbacks to update the status lines.

Change-Id: I6b3975b703a7d90bac8d0fe29fbc0f1d9c5e0e7d