Merge "Add secure key storage api for keymaster and implement pure software secure key storage to mock secure hardware." am: f6775ab03c am: 956d41a334

Original change: https://android-review.googlesource.com/c/platform/system/keymaster/+/1579865

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I7df297a01c3812369a30b659396c0aeeb1e10f2a