Merge "Revert "Revert "Release cblocks back to the free pool""" into sc-dev am: cc265a58 am: 3b75c63a

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/14807907

Change-Id: Ic2f32a9a26540ff150310e238d5f0ad4ef18722b