Public HPKE API. am: 89a46d5584

Original change: https://android-review.googlesource.com/c/platform/art/+/2967375

Change-Id: I14b5f7301a2cc63e0da6397f4d123c57bac4c16a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>