Base: fix Clock showing on lockscreen after reboot

how to reproduce

try enable center clock, and then reboot, you will see, clock is showing on lockscreen, and need to lock/unlock to hide again

user will not report this issue until they enabled center clock, and watch device reboot

Change-Id: I1a038bb258ad03bacfa4b528c2acbb030ab8b024

Conflicts:
	packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java
	packages/SystemUI/src/com/android/systemui/statusbar/policy/Clock.java
	packages/SystemUI/src/com/android/systemui/statusbar/policy/ClockCenter.java