DockBatteryMeter: Avoid double detach when view is rebuilt

If the view is reconstructed for some reason (like applying a theme)
on a device without a dock battery, it'll try to detach and unregister
twice. The second unregister will case an NPE since the first one
killed the listener. Fixit.

Change-Id: Idcc0c7c87ef205ddc085a9e036fe630afd9d7012
Merge "DockBatteryMeter: Avoid double detach when view is rebuilt" into cm-11.0
[1/4] base: allow disabling non intrusive incall ui

Change-Id: Ibe9c65f1fe024a859d98d96fd86199607a1060de
[1/3] Base: Flip to Mute/Reject Call

Saving flip action value to settings container

Telephony: https://gerrit.omnirom.org/#/c/4670/
InCallUI: https://gerrit.omnirom.org/#/c/4669/

Change-Id: Ie72dda49d78b23b9bc7d8a886f6916f678c918d1

Conflicts:
	core/java/android/provider/Settings.java