Merge "Restore trimMemory behaviour from T" into udc-dev am: 90c9dbf7b9

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/24733945

Change-Id: Ic2768f2ae2bd8f6979b2a52a5285a9ba53a3b6ea
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>