GS3 (D2) U.S. Variants support

OS = jb43

d2vzw = GS3 Verizon
d2spr = GS3 Sprint
d2tmo = GS3 T-Mobile
d2att = GS3 AT&T
d2mtr = GS3 Metropcs
d2usc = GS3 US Cellular

Signed-off-by: ayysir <dresadd09691@gmail.com>