Added support for WPWebViewClient to pass the token for image requests.

Moved `isImageUrl` method to `UrlUtils` since it is being used in two places now.

Fixes #2444

Author: roundhill

WordPressUtils/src/main/java/org/wordpress/android/util/UrlUtils.java

@@ -1,6 +1,7 @@
 package org.wordpress.android.util;
 
 import android.net.Uri;
+import android.text.TextUtils;
 import android.webkit.MimeTypeMap;
 import android.webkit.URLUtil;
 
@@ -195,4 +196,14 @@ public static boolean isValidUrlAndHostNotNull(String url) {
         }
         return true;
     }
+
+    // returns true if the passed url is for an image
+    public static boolean isImageUrl(String url) {
+        if (TextUtils.isEmpty(url)) return false;
+
+        String cleanedUrl = removeQuery(url.toLowerCase());
+
+        return cleanedUrl.endsWith("jpg") || cleanedUrl.endsWith("jpeg") ||
+                cleanedUrl.endsWith("gif") || cleanedUrl.endsWith("png");
+    }
 }