Remove PasswordMetrics#validatePassword() am: 2b32467e37 am: 615ca048a5

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2775383

Change-Id: Ief46ce64492ae9828638bf25dad7504648397f16
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>