Remove unused Android.mk under device/google/felix am: 1890f3cb8b am: be68db3120

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

Change-Id: Ibe6badf4390c8bc299596cc8e9eaad5c74c2ab8f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>