Reduce visibility of ReactImageDownloadListener

Summary:
In an attempt to reduce footprint of React Native Android public APIs we are reducing visibility of classes and interfaces that are not meant to be used publicly OR are public but have no usages.
As part of our analysis, which involved looking for usages inside the Meta codebase and code search in OSS, we've detected that this class/interface is public but it's not used from other packages.

If you are using this class or interface please comment in this PR and we will restate the public access.

bypass-github-export-checks

changelog: [Android][Changed] Reducing visibility of ReactImageDownloadListener

Reviewed By: arushikesarwani94

Differential Revision: D49803289

fbshipit-source-id: 19d4c3403449dd9b928963b274362662375b7545

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/views/image/ReactImageDownloadListener.java

@@ -16,7 +16,7 @@
 import com.facebook.drawee.drawable.ForwardingDrawable;
 import javax.annotation.Nullable;
 
-public class ReactImageDownloadListener<INFO> extends ForwardingDrawable
+class ReactImageDownloadListener<INFO> extends ForwardingDrawable
     implements ControllerListener<INFO> {
 
   private static final int MAX_LEVEL = 10000;