fix(types): Update Typescript definition file (#1597)

index.d.ts

@@ -41,6 +41,29 @@ declare class WebView extends Component<WebViewProps> {
      * Focuses on WebView redered page.
      */
     requestFocus: () => void;
+    
+     /**
+     * Posts a message to WebView.
+     */
+    postMessage: (message: string) => void;
+    
+     /**
+     * (Android only)
+     * Removes the autocomplete popup from the currently focused form field, if present.
+     */
+    clearFormData: () => void;
+
+     /**
+     * (Android only)
+     * Clears the resource cache. Note that the cache is per-application, so this will clear the cache for all WebViews used.
+     */
+    clearCache: (clear: boolean) => void;
+
+     /**
+     * (Android only)
+     * Tells this WebView to clear its internal back/forward list.
+     */
+    clearHistory: () => void;
 }
 
 export {WebView};