Allow constructing a PIN LockscreenCredential with mInvalidChars am: 220d6a284e am: 9a3ec893bb am: 46c9ee64c4

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2775379

Change-Id: I50e415c9bb3ad599f3660c3d42313de7926a3251
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>