Introduce Secretkeeper HAL interface am: 18cafa0a11

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/2695089

Change-Id: I9ee10451fc5a1919d30bd4a51e81b19db62bfb19
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>