Method GetFramesAtIndex haven't been added into Xamarin.Android.Supportv28.0.0.1

[jessiezh0320]

Xamarin.Android Version (eg: 6.0):

Xamarin.Android.Support.XX  v28.0.0.1 

Operating System & Version (eg: Mac OSX 10.11):

Support Libraries Version (eg: 23.3.0):

Describe your Issue:

According to the android document , method getFrameAtIndex() in class
android.media.MediaMetadataRetriever have been added in API level 28.
https://developer.android.com/reference/android/media/MediaMetadataRetriever.html#getFramesAtIndex(int,%20int,%20android.media.MediaMetadataRetriever.BitmapParams)

But I couldn't find the method getFrameAtIndex() in xamarin android.

Steps to Reproduce (with link to sample solution if possible):

1. create a new xamarin android project

2. install the Xamarin.Android.Support.Design v28.0.0.1

3. write code as follows

   MediaMetadataRetriever retriever = new MediaMetadataRetriever();

But i couldn't find the method getFrameAtIndex .

Include any relevant Exception Stack traces, build logs, adb logs:

[thinkbigsoftware]

Please also note that there have been several metatdata keys added in API 28. Specifically useful to the above method is METADATA_KEY_VIDEO_FRAME_COUNT.