Removed unused Android.mk under device/google/contexthub am: 224d08b385

Original change: https://android-review.googlesource.com/c/device/google/contexthub/+/3099157

Change-Id: I9ca508659bc765f7f18b5b6467690c74e7d7f04c
Signed-off-by: Automerger Merge Worker <[email protected]>