New interface EncodedImageBufferInterface, replacing use of CopyOnWriteBuffer

Bug: webrtc:9378
Change-Id: I62b7adbd9dd539c545b5b1b1520721482a4623c4
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/138820
Reviewed-by: Kári Helgason <kthelgason@webrtc.org>
Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28317}

modules/video_coding/encoded_frame.h

@@ -56,6 +56,7 @@ class VCMEncodedFrame : protected EncodedImage {
   using EncodedImage::data;
   using EncodedImage::set_size;
   using EncodedImage::SetColorSpace;
+  using EncodedImage::SetEncodedData;
   using EncodedImage::SetSpatialIndex;
   using EncodedImage::SetSpatialLayerFrameSize;
   using EncodedImage::SetTimestamp;