Piggybacking simulcast id and ALR experiment id into video content type extension.

webrtc/sdk/android/src/jni/androidmediaencoder_jni.cc

Index: webrtc/sdk/android/src/jni/androidmediaencoder_jni.cc
diff --git a/webrtc/sdk/android/src/jni/androidmediaencoder_jni.cc b/webrtc/sdk/android/src/jni/androidmediaencoder_jni.cc
index 0aa5a5112c30b744138d4eeba51bfc56ff619394..f79a2e5eecaafc79b836b506cf7bf4b0bd122b44 100644
--- a/webrtc/sdk/android/src/jni/androidmediaencoder_jni.cc
+++ b/webrtc/sdk/android/src/jni/androidmediaencoder_jni.cc
@@ -1159,8 +1159,8 @@ bool MediaCodecVideoEncoder::DeliverPendingOutputs(JNIEnv* jni) {
       image->rotation_ = output_rotation_;
       image->content_type_ =
           (codec_mode_ == webrtc::VideoCodecMode::kScreensharing)
-              ? webrtc::VideoContentType::SCREENSHARE
-              : webrtc::VideoContentType::UNSPECIFIED;
+              ? webrtc::VideoContentType::Screenshare()
+              : webrtc::VideoContentType::Unspecified();
       image->timing_.flags = webrtc::TimingFrameFlags::kInvalid;
       image->_frameType =
           (key_frame ? webrtc::kVideoFrameKey : webrtc::kVideoFrameDelta);