FWB: Hover enable from Settings (1/2)

I don't like beeing terorized with halo icon in
expanded statusbar all the time.
Add a setting to AICP extras for Hover

Change-Id: Ie3feb8925ea21f429e7c6138e64d639d8a9a876c

Conflicts:
	packages/SystemUI/res/layout/status_bar_expanded_header.xml
	packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java
Revert "FWB: Hover enable from Settings (1/2)"

This reverts commit c53f4d2982970960820f201f668986e970b64d6a.