Determine scalability mode if not explicilty set for AV1.

Bug: none
Change-Id: I86298b8a57300ed1d824cf6ba8f5daeec6af7315
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/262242
Reviewed-by: Erik Språng <sprang@webrtc.org>
Commit-Queue: Philip Eliasson <philipel@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#36879}
diff --git a/modules/video_coding/video_codec_initializer.cc b/modules/video_coding/video_codec_initializer.cc
index 80b9dc9..1cec6d2 100644
--- a/modules/video_coding/video_codec_initializer.cc
+++ b/modules/video_coding/video_codec_initializer.cc
@@ -263,7 +263,11 @@
       break;
     }
     case kVideoCodecAV1:
-      if (SetAv1SvcConfig(video_codec)) {
+      if (SetAv1SvcConfig(video_codec,
+                          /*num_temporal_layers=*/
+                          streams.back().num_temporal_layers.value_or(1),
+                          /*num_spatial_layers=*/
+                          std::max<int>(config.spatial_layers.size(), 1))) {
         for (size_t i = 0; i < config.spatial_layers.size(); ++i) {
           video_codec.spatialLayers[i].active = config.spatial_layers[i].active;
         }