[Fuchsia] Tie image pipe registration to a flag

This CL fixes the error from the previous CL where we always
registered videos with an image pipe.

Bug: 1127984
Change-Id: I54a90068a96145c354a6ec2f874e415b8824e422
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2518136Reviewed-by: Sergey Ulanov <sergeyu@chromium.org>
Commit-Queue: Sergey Ulanov <sergeyu@chromium.org>
Auto-Submit: Emircan Uysaler <emircan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#824192}

media/filters/fuchsia/fuchsia_video_decoder.cc

@@ -1032,7 +1032,7 @@ void FuchsiaVideoDecoder::InitializeOutputBufferCollection(
           output_buffer_collection_id_,
           collection_token_for_gpu.Unbind().TakeChannel(),
           gfx::BufferFormat::YUV_420_BIPLANAR, gfx::BufferUsage::GPU_READ,
-          true /*register_with_image_pipe*/);
+          use_overlays_for_video_ /*register_with_image_pipe*/);
 
   // Pass new output buffer settings to the codec.
   fuchsia::media::StreamBufferPartialSettings settings;