Allow modules to override the default NOTICE file.

It's useful in projects where different top level modules have
different licenses associated with them.

(cherry picked from commit 3026f4daf11b2d4729559d49624e748a82f15495)

Change-Id: I71b20d6f979c0f50562f4f44b2af1f3ec2909444
diff --git a/core/notice_files.mk b/core/notice_files.mk
index cf2dad6..e7f8974 100644
--- a/core/notice_files.mk
+++ b/core/notice_files.mk
@@ -2,7 +2,11 @@
 ## Track NOTICE files
 ###########################################################
 
+ifneq ($(LOCAL_NOTICE_FILE),)
+notice_file:=$(strip $(LOCAL_NOTICE_FILE))
+else
 notice_file:=$(strip $(wildcard $(LOCAL_PATH)/NOTICE))
+endif
 
 ifeq ($(LOCAL_MODULE_CLASS),GYP)
   # We ignore NOTICE files for modules of type GYP.