App sidebar: notify if app is not installed

better than force close

Change-Id: I9eebe1a3a4be2dad16ed9a8cff9c0694900d833d

Conflicts:
	packages/SystemUI/res/values/cm_strings.xml

Conflicts:
	packages/SystemUI/res/values/crom_strings.xml
AppSideBar : fix view derp with side changing