message: Add default values for VideoEncoderFactory::CodecInfo
  So that applications can construct a default struct without naming the
  members.
  Cr-Commit-Position: refs/heads/master@{#31742}
diff: @@ -30,13 +30,13 @@ class VideoEncoderFactory {
  struct CodecInfo {
  // |is_hardware_accelerated| is true if the encoders created by this factory
  // of the given codec will use hardware support.
  - bool is_hardware_accelerated;
  + bool is_hardware_accelerated = false;
  // |has_internal_source| is true if encoders created by this factory of the
  // given codec will use internal camera sources, meaning that they don't
  // require/expect frames to be delivered via webrtc::VideoEncoder::Encode.
  // This flag is used as the internal_source parameter to
  // webrtc::ViEExternalCodec::RegisterExternalSendCodec.
  - bool has_internal_source;
  + bool has_internal_source = false;
  };
  // An injectable class that is continuously updated with encoding conditions
  