Merge "Keystore 2.0: Add keystore engine grant string convenience functions." am: 4da629d9be am: 7e74123b72

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1569501

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I57b0b1385d023db8476dd8e8978975938e1e4d04