Remove empty Android.mk

This empty file was used to shadow Android.mk files present in
subfolders earlier. The Android.mk in subfolders are now under
ifdef NDK_ROOT and thus they don't impact the builds in Android
source tree making the empty Android.mk redundant.

Bug: 322108371
Test: Treehugger
Change-Id: I5d3de13da631a93dcf26dc0739dd8ed3cb1eae54
1 file changed