Revert "Convert Keyguard tests to Robolectric tests" am: 122768bf80 am: 49da8b693d

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/21340156

Change-Id: I13a15db660acaebfc50fbc51c5ffcdccaef25ce7
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>