Suppress source release failures.

This is similar to suppression of failures disabling the
renderers (in the block above).
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=123847812

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

@@ -516,7 +516,12 @@ import java.util.concurrent.atomic.AtomicInteger;
       }
     }
     if (source != null) {
+      try {
         source.release();
+      } catch (RuntimeException e) {
+        // There's nothing we can do.
+        Log.e(TAG, "Source release failed.", e);
+      }
       source = null;
     }
   }