Merge "Make TaskStackListener work in freeform mode" into udc-dev am: 14a73941

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/21470899



Change-Id: I15db815f5821e4864c33261f76759e7fa0b8a275
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>