Add and use PasswordMetrics#validateCredential() am: 811f091fff am: 5074551422

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2775377

Change-Id: I2d944f07c9c359d2b7c6345b6d980d3b156ce4ac
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>