OSV-2020-1018 Heap-use-after-free in draco::Metadata::AddSubMetadata

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=23342 Crash type: Heap-use-after-free READ 8 Crash state: draco::Metadata::AddSubMetadata draco::MetadataDecoder::DecodeMetadata draco::MetadataDecoder::DecodeGeometryMetadata...