[LSC] Add LOCAL_LICENSE_KINDS to external/libgav1

Added SPDX-license-identifier-Apache-2.0 to:
  Android.bp

Bug: 68860345
Bug: 151177513
Bug: 151953481

Test: m all

Exempt-From-Owner-Approval: janitorial work

Change-Id: I03cf32c24eecd831138c8d8887697130d1fff3c2
Merged-in: I03cf32c24eecd831138c8d8887697130d1fff3c2