Fix buffer mapping of BLOB buffers

... in case the allocation size doesn't match the buffer size.
Also unify the buffer mapping, since it's not necessary to handle BLOB
buffers in a special way.

Bug: 338995824
Test: atest VirtualCameraCaptureTest
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:8d4197ed02119d93674c429bb5367747bf33a8ed)
Merged-In: I368850dba86377252c941b6935a615cb5cfca785
Change-Id: I368850dba86377252c941b6935a615cb5cfca785
1 file changed