This patch is a follow up to https://webrtc-review.googlesource.com/c/src/+/212743 which broke downstream fuzzer :( prior to https://webrtc-review.googlesource.com/c/src/+/212743, RtpVideoLayersAllocationExtension::AllocationIsValid returns false if rtp_stream_index > max(layer.rtp_stream_index) After https://webrtc-review.googlesource.com/c/src/+/212743, 0 spatial layers is supported, so the AllocationIsValid is updated to allow any value if not layers are present. Bug: webrtc:12000 Change-Id: Ib3e64ecb621f795b9126442c50969f5178c85a37 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/212901 Commit-Queue: Jonas Oreland <jonaso@webrtc.org> Reviewed-by: Danil Chapovalov <danilchap@webrtc.org> Cr-Commit-Position: refs/heads/master@{#33551}