Remove unused Android.mk under device/google/felix am: 1890f3cb8b

Original change: https://android-review.googlesource.com/c/device/google/felix/+/2835912

Change-Id: Ia2da9795fd437e3ed81b45730f9163391017f2f9
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>