Initial support for ARM64
Initial support for ARM64

Existing host-side support for Cuttlefish is being built for the time
being only for x86_64 due to limitaitons in the Android build system.
Until that changes, we rely on qemu-user-static to run x86_64 binaries
on aarch64.

Signed-off-by: Iliyan Malchev <b9962a40c76f189681da2829a74a26cab77021ea@google.com>

google/android-cuttlefish,google/android-cuttlefish,google/android-cuttlefish,google/android-cuttlefish,google/android-cuttlefish,google/android-cuttlefish,google/android-cuttlefish