Fix file permissions for source code files

Removed file execute permissions for:
 - bta/include/bta_hh_co.h
 - embdrv/sbc/decoder/Android.mk
 - embdrv/sbc/Android.mk
 - embdrv/Android.mk
 - btif/co/bta_ag_co.cc

Test: visual inspection of file permissions
Change-Id: I746debb1e8ceaa1cc14f867641b25cb42c04c7be