-Added loader eviction to avoid spawning too many threads in MediaSourceManager.

-Added nonnull and final constraints to variables in MediaSourceManager.
-Added nonnull and final constraints on context related objects in BasePlayer.
-Fixed Hls livestreams crashing player when behind live window for too long.
-Fixed cache miss when InfoCache key mismatch between StreamInfo and StreamInfoItem.

app/src/main/java/org/schabi/newpipe/fragments/detail/VideoDetailFragment.java

@@ -322,7 +322,7 @@ public class VideoDetailFragment
         if (serializable instanceof StreamInfo) {
             //noinspection unchecked
             currentInfo = (StreamInfo) serializable;
-            InfoCache.getInstance().putInfo(currentInfo);
+            InfoCache.getInstance().putInfo(serviceId, url, currentInfo);
         }
 
         serializable = savedState.getSerializable(STACK_KEY);