Use conventional style ../{Default|Disabled|Enabled} with parameter
inter_layer_pred_mode:{off|on|onkeypic} which maps directly to
InterLayerPredMode enum.
Bug: chromium:949536
Change-Id: If34e789b031d0db3eb2748b0b824492237ad5187
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/137800
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Commit-Queue: Sergey Silkin <ssilkin@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28008}