Remove unused Android.mk under device/google/redfin am: a9544cd2ed

Original change: https://android-review.googlesource.com/c/device/google/redfin/+/2836011

Change-Id: I0ac7b7a8f95e33f5cd88b4be0d9e4ec84b93a0c0
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>