Revert "Settings: Add HeadsUp setting."

This reverts commit bf1c0b404655f2efc2b14fae2911173b5f3c27e5.

Conflicts:
	res/values/crom_strings.xml
HeadsUp [2/2]

Change-Id: Ib7a59145843bedb16aacc87bf6d3c6da143e8d3e
HeadsUp: User configurable timeout [2/2]

Change-Id: I6c55636205237044891324f0dd855046aaafb256
HeadsUp: option to launch in floating window (2/2)

Change-Id: Ibbdbf7957738d2301eacc190a0ab408ce20350b5