[LSC] Add LOCAL_LICENSE_KINDS to external/libwebm am: a26f3396c1 am: db06ddaca6

Original change: https://android-review.googlesource.com/c/platform/external/libwebm/+/1588663

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Idba69c66955aae4c6a8ba9380bc43b972862f08e