Move android-all generations to /external/robolectric am: 3a3ed76c5b

Original change: https://android-review.googlesource.com/c/platform/test/robolectric-extensions/+/2914868

Change-Id: Ie0ebfe8739ef87327eadcb156adb3f4da05569ce
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>