Remove prebuilt SamsungServiceMode and common_sgs.mk. Overlays need to be set per device basis.

Change-Id: I5c8808a6313d3cff4b7a4f7e7863e42c2b0d2705
Signed-off-by: Josue Rivera <prbassplayer@gmail.com>
Merge "Remove prebuilt SamsungServiceMode and common_sgs.mk. Overlays need to be set per device basis." into jb4.3