RequestHeaders not passed through to ExoPlayer

I'm setting the authorization header with the following code and then attemping to play the audio file.

CrossMediaManager.Current.RequestHeaders["Authorization"] = $"Bearer {authToken}";
await CrossMediaManager.Current.Play(fileUrl);

When I examine the HTTP traffic in Fiddler, there are two requests issued. The first request has the correct authorization header but the second request issued by ExoPlayerLib doesn't. This means the second request fails because the request is unauthorized.
See below for Fiddler HTTP raw data.

GET http://localdev:4501/Audio/GetAudio?ContentType=R&ContentID=2210514 HTTP/1.1
Authorization: Bearer eyJhbGciOiJSUzI1NiIsImtpZCI6IkZCMDEwMEM5MDI4MUVGRkFENjUxRDQ0RkYwRDREMDE2OTBCQUNDMjkiLCJ0eXAiOiJKV1QiLCJ4NXQiOiItd
User-Agent: stagefright/1.2 (Linux;Android 8.1.0)
Host: localdev:4501
Connection: Keep-Alive
Accept-Encoding: gzip

GET http://localdev:4501/Audio/GetAudio?ContentType=R&ContentID=2210514 HTTP/1.1
User-Agent: Test.Mobile.Phone.Android/1.8 (Linux;Android 8.1.0) ExoPlayerLib/2.9.6
Accept-Encoding: identity
Host: localdev:4501
Connection: Keep-Alive

Start at the CrossMediaManager.Current.RequestHeaders and Play entry points, then trace the Android ExoPlayerLib request path described in the Fiddler output. Compare the first authorized request with the second request and verify that the Authorization header is retained for ExoPlayer's request; done means both requests carry the required header.

Written by the indexing model from the issue text.