Setting different number of temporal layers is supported by SimulcastEncodeAdapter and LibvpxVp8Encoder will fallback to SimulcastEncoderAdapter if InitEncode fails. Bug: none Change-Id: I8a09ee1e6c70a0006317957c0802d019a0d28ca2 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/228642 Reviewed-by: Erik Språng <sprang@webrtc.org> Reviewed-by: Harald Alvestrand <hta@webrtc.org> Commit-Queue: Åsa Persson <asapersson@webrtc.org> Cr-Commit-Position: refs/heads/master@{#34785}