Merge "Add test method...

Merge "Add test method UserLifecycleStressTest.switchToExistingGuestAndStartOverStressTest" into tm-dev am: e1062bc7

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/17749723



Change-Id: I6ef829fbcd1cacee9385a7ad1b16acca80d61b35
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>