C2AllocatorGralloc: Limit Gralloc4Mapper_lock to T and above

Gralloc4Mapper_lock() returns few wrong parameters when called
on few devices running older Android versions as part of mainline
module.

Since this function was added in Android T to support vendor P010
format and P010 support is Android T and above, this function is
now limited to devices running Android T and above.

Bug: 237366327
Test: atest CtsMediaCodecTestCases:EncodeVirtualDisplayTest \
 CtsMediaV2TestCases:android.mediav2.cts.CodecEncoderSurfaceTest

Change-Id: I58590098d47bb3eb6d871235c200a5bb82faed25