Handle TrackStream transitions in isSourceReady.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=125669080

library/src/main/java/com/google/android/exoplayer/TrackRenderer.java

@@ -370,7 +370,7 @@ public abstract class TrackRenderer implements ExoPlayerComponent {
    * @return True if the source is ready. False otherwise.
    */
   protected final boolean isSourceReady() {
-    return stream.isReady();
+    return readEndOfStream ? streamIsFinal : stream.isReady();
   }
 
   // Abstract methods.