feat(android): expose videoPlayer buffer

android/modules/media/src/java/android/widget/TiVideoView8.java

@@ -552,6 +552,9 @@ public boolean onError(MediaPlayer mp, int framework_err, int impl_err)
 			public void onBufferingUpdate(MediaPlayer mp, int percent)
 			{
 				mCurrentBufferPercentage = percent;
+				if (mPlaybackListener != null) {
+					mPlaybackListener.onBuffer(percent);
+				}
 			}
 		};
 

android/modules/media/src/java/ti/modules/titanium/media/TiPlaybackListener.java

@@ -19,4 +19,6 @@ public interface TiPlaybackListener {
 	void onSeekingBackward();
 
 	void onSeekingForward();
+
+	void onBuffer(int value);
 }

android/modules/media/src/java/ti/modules/titanium/media/TiUIVideoView.java

@@ -371,6 +371,12 @@ public void onSeekingForward()
 		getPlayerProxy().onSeekingForward();
 	}
 
+	@Override
+	public void onBuffer(int value)
+	{
+		getPlayerProxy().onBuffer(value);
+	}
+
 	@Override
 	public void onSeekingBackward()
 	{

android/modules/media/src/java/ti/modules/titanium/media/VideoPlayerProxy.java

@@ -686,6 +686,13 @@ public void onSeekingBackward()
 		firePlaybackState(MediaModule.VIDEO_PLAYBACK_STATE_SEEKING_BACKWARD);
 	}
 
+	public void onBuffer(int value)
+	{
+		KrollDict kd = new KrollDict();
+		kd.put("percentage", value);
+		fireEvent("buffer", kd);
+	}
+
 	private String getActionName(int action)
 	{
 		switch (action) {

apidoc/Titanium/Media/VideoPlayer.yml

@@ -205,6 +205,16 @@ methods:
     summary: Stops playing the video.
 
 events:
+  - name: buffer
+    summary: |
+        Fired when the video is loading/buffering.
+    properties:
+      - name: percentage
+        summary: Percentage of the video that is buffered/loaded.
+        type: Number
+    since: '12.1.0'
+    platforms: [android]
+
   - name: complete
     summary: Fired when movie playback ends or a user exits playback.
     description: |