OSV-2021-909 Heap-buffer-overflow in OT::CPALV1Tail::serialize

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=35672 Crash type: Heap-buffer-overflow READ 2 Crash state: OT::CPALV1Tail::serialize OT::CPAL::subset bool trysubset...