Merge "Revert "Revert "Release cblocks back to the free pool""" into sc-dev am: cc265a58 am: 81a2e619 am: dc9e7b9b

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

Change-Id: Ib79c5d3e86089679ae9e67c5a1e7e9e2b86478f2