buildinfo: only set ro.build.product on non-unified devices

Change-Id: I5dccba2172dade3dacc55d832a2042fce306b5f5
(cherry picked from commit 8409482314531f4eae0c72c582ffc8f0c63c3a98)
core: Enable -mcpu=cortex-a9 flag for Cortex-A9 cpu variant

Change-Id: I9294a518bcdc21ccbae72eadd9f3c1a12982d028
(cherry picked from commit e65e60159204810fa49751316cea1dfb3877c8df)
core: armv7-a-neon.mk: Add missing endif

Change-Id: Id6f9c952d01d3c980115a52605d9c86038b3b5bd
(cherry picked from commit 350d5ea211e120856d6d0e4cf1057980cb417844)