Fix the build when using findleaves.py
This doesn't seem to affect the Kati emulation (at least on Linux), but
findleaves.py on both Mac and Linux checks for duplicate files (via
inode) and only emits build/{target,tools}/Android.mk instead of that
and build/make/{target,tools}/Android.mk.
Bug: 64397960
Test: build/tools/findleaves.py --prune=.git --prune=.repo --dir=. Android.mk
Test: m -j signapk
Change-Id: Ie6219a809e403e6cc9371b5c0370c7925a592a0d
diff --git a/Android.mk b/Android.mk
new file mode 100644
index 0000000..5053e7d
--- /dev/null
+++ b/Android.mk
@@ -0,0 +1 @@
+include $(call all-subdir-makefiles)