Merge "Remove obsolete Android.mk for clang" into main am: 7a67a37a65

Original change: https://android-review.googlesource.com/c/platform/external/clang/+/2984091

Change-Id: Ic21d43c19c147445a24fb5c6baec2d40fea40716
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>