Added a more descriptive error message for AuthorizationExceptions

Author: KevinvdBurg

android/src/main/java/com/rnappauth/RNAppAuthModule.java

@@ -1019,7 +1019,12 @@ private void handleAuthorizationException(final String fallbackErrorCode, final
         if (ex.getLocalizedMessage() == null) {
             promise.reject(fallbackErrorCode, ex.error, ex);
         } else {
-            promise.reject(ex.error != null ? ex.error: fallbackErrorCode, ex.getLocalizedMessage(), ex);
+          String message = ex.getLocalizedMessage();
+          if(ex.getCause() != null) {
+            message += "- Cause: " + ex.getCause().getLocalizedMessage();
+          }
+
+          promise.reject(ex.error != null ? ex.error: fallbackErrorCode, message, ex);
         }
     }