frameworks/base: Update quick launch shortcut icons/resources

Update the existing icons and add "xxhdpi" versions created
from a vector template. This commit cleans also the resource
files a bit up.

Screenshot: http://goo.gl/6CrMYr

Change-Id: I45abee5cf13cd239eb5b4402019afac28d6d5952

Conflicts:
	core/java/com/android/internal/util/cm/NavigationRingConstants.java
	core/java/com/android/internal/util/cm/NavigationRingHelpers.java
	core/res/res/values/dimens.xml
	core/res/res/values/symbols.xml
	packages/SystemUI/src/com/android/systemui/cm/ActionTarget.java
SystemUI: add left and right virtual buttons while typing (1/2)

Change-Id: Iea446443d33ff305765e47c86523b619676116ac

Conflicts:
	packages/SystemUI/src/com/android/systemui/statusbar/phone/NavbarEditor.java
	packages/SystemUI/src/com/android/systemui/statusbar/phone/NavigationBarView.java