Merge "Merge "Remove unused restore-mode logic in ActivityStack" into rvc-dev am: 99ed6ce7 am: 81f2ea40 am: 08bf4009" into rvc-qpr-dev-plus-aosp am: c1147ed3

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/11694346

Change-Id: Icba105b67e178aedb598103dc7d902605e00c3c1