Cherry-pick two BufferItem changes

libcameraservice: Stop using IGBC::BufferItem
(cherry picked from commit 027c772ed30ddd32808df669e37a53e9b97b1f99)

libstagefright: Stop using IGBC::BufferItem
(cherry picked from commit 983e2be81f9ea767ae4d8b19669c1c080ecf58d4)
12 files changed