Merge "Keystore 2.0 SPI: Implement modification time." am: d2e7c2e000

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1530772

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ib7782fe0d5005b0249bbe459af10f8c1a395f482