Merge "Fix kotlin nullable errors in CredentialManager" into udc-dev-plus-aosp am: 64f08db3

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/24517136



Change-Id: I91ea6bad961fb364fe785e05f6e7f3f443d04016
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>