c2-codecs: bump buffer size to 6M am: f0619e5ebd

Original change: https://googleplex-android-review.googlesource.com/c/device/generic/goldfish-opengl/+/17574055

Change-Id: Iee27ca97f6854f7fbc70deeded64d07d27250c4c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>