Improve comment for why license_type by_exception

Test: m all

Bug: 151953481
Bug: 151177513
Bug: 67772237

Exempt-From-Owner-Approval: janitorial work

Change-Id: I198736e748b74b4f96dba88d7cbddb7663e87988
diff --git a/METADATA b/METADATA
index 1fbda08..aabda36 100644
--- a/METADATA
+++ b/METADATA
@@ -2,6 +2,22 @@
 #     CONSULT THE OWNERS AND opensource-licensing@google.com BEFORE
 #     DEPENDING ON IT IN YOUR PROJECT. ***
 third_party {
-  # would be NOTICE save for drm/mediadrm/plugins/clearkey/hidl/
+  # would be NOTICE save for Widevine Master License Agreement in:
+  #   drm/mediadrm/plugins/clearkey/hidl/DeviceFiles.cpp
+  #   drm/mediadrm/plugins/clearkey/hidl/MemoryFileSystem.cpp
+  #   drm/mediadrm/plugins/clearkey/hidl/include/DeviceFiles.h
+  #   drm/mediadrm/plugins/clearkey/hidl/protos/DeviceFiles.proto
+  #   drm/mediadrm/plugins/clearkey/hidl/include/MemoryFileSystem.h
+  # and patent disclaimers in:
+  #   media/codec2/components/aac/patent_disclaimer.txt
+  #   media/codec2/components/amr_nb_wb/patent_disclaimer.txt
+  #   media/codec2/components/mp3/patent_disclaimer.txt
+  #   media/codec2/components/mpeg4_h263/patent_disclaimer.txt
+  #   media/codecs/amrnb/patent_disclaimer.txt
+  #   media/codecs/amrwb/dec/patent_disclaimer.txt
+  #   media/codecs/amrwb/enc/patent_disclaimer.txt
+  #   media/codecs/m4v_h263/patent_disclaimer.txt
+  #   media/codecs/mp3dec/patent_disclaimer.txt
+  #   media/libstagefright/codecs/aacenc/patent_disclaimer.txt
   license_type: BY_EXCEPTION_ONLY
 }