Ed25519: Indicate Android Keystore supports it am: c6ec3dfa73 am: 8fed35c972

Original change: https://googleplex-android-review.googlesource.com/c/platform/libcore/+/18346846

Change-Id: I1733be3ac474d96d8e3372c8dc52175ff7216adc
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>