Merge "Collect header files in subdirectories" am: 78a68df634

Original change: https://android-review.googlesource.com/c/platform/development/+/2469200

Change-Id: Iad013af14f8a9c955daa5e3e7ee72dbb6472069b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>