Use Guava's AbstractFuture to implement GceFuture.

This required adding Guava to the java Android.mk file, but allows
GceFuture to implement the more powerful ListenableFuture type with less
implementation.

AbstractFuture docs:
https://google.github.io/guava/releases/20.0/api/docs/com/google/common/util/concurrent/AbstractFuture.html

Bug: 110903523
Test: Ran cf_x86_64_phone-userdebug locally.
Change-Id: I305646473f3a0710f5315285912f4e106ed272c7
2 files changed
tree: 030f456b9c50a4cbab59831d6073a8c167ad9b22
  1. common/
  2. guest/
  3. host/
  4. tests/
  5. tools/
  6. Android.bp
  7. Android.mk
  8. OWNERS