[LSC] Add LOCAL_LICENSE_KINDS to external/fft2d Added legacy_by_exception_only legacy_notice to: Android.bp Bug: 68860345 Bug: 151177513 Bug: 151953481 Test: m all Exempt-From-Owner-Approval: janitorial work Change-Id: I9b3f8ded14fb4161dbfe5d7c3f5b07cead5b8db4