[LSC] Add LOCAL_LICENSE_KINDS to external/libvpx

Added SPDX-license-identifier-BSD to:
  libvpx/third_party/libwebm/Android.mk

Bug: 68860345
Bug: 151177513
Bug: 151953481

Test: m all
Change-Id: I6f7c84479f15e43ad7721f75e06d664ed2db19b1
1 file changed