Android.mk: import LICENSE indicators from AOSP

https://android-review.googlesource.com/c/platform/external/libvpx/+/1858286
https://android.googlesource.com/platform/external/libvpx/+/b35704ee444f6e2533fcbc2efdcb4bd47f5eb912

Change-Id: Ia884434083f85abc291262796c9ff1cd0dcea45a
diff --git a/Android.mk b/Android.mk
index b46ba10..1185198 100644
--- a/Android.mk
+++ b/Android.mk
@@ -14,4 +14,7 @@
                   mkvmuxer/mkvmuxer.cc \
                   mkvmuxer/mkvmuxerutil.cc \
                   mkvmuxer/mkvwriter.cc
+LOCAL_LICENSE_KINDS := SPDX-license-identifier-BSD
+LOCAL_LICENSE_CONDITIONS := notice
+LOCAL_NOTICE_FILE := $(LOCAL_PATH)/LICENSE.TXT $(LOCAL_PATH)/PATENTS.TXT
 include $(BUILD_STATIC_LIBRARY)