don't call super.shouldOverrideUrlLoading

packages/webview_flutter/android/src/main/java/io/flutter/plugins/webviewflutter/FlutterWebView.java

@@ -4,7 +4,9 @@
 
 package io.flutter.plugins.webviewflutter;
 
+import android.annotation.TargetApi;
 import android.content.Context;
+import android.os.Build;
 import android.view.View;
 import android.webkit.WebStorage;
 import android.webkit.WebView;
@@ -139,6 +141,7 @@ private void updateSettings(MethodCall methodCall, Result result) {
     result.success(null);
   }
 
+  @TargetApi(Build.VERSION_CODES.KITKAT)
   private void evaluateJavaScript(MethodCall methodCall, final Result result) {
     String jsString = (String) methodCall.arguments;
     if (jsString == null) {

packages/webview_flutter/android/src/main/java/io/flutter/plugins/webviewflutter/FlutterWebViewClient.java

@@ -35,7 +35,7 @@ void setHasNavigationDelegate(boolean hasNavigationDelegate) {
   @Override
   public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {
     if (!hasNavigationDelegate) {
-      return super.shouldOverrideUrlLoading(view, request);
+      return false;
     }
     notifyOnNavigationRequest(
         request.getUrl().toString(), request.getRequestHeaders(), view, request.isForMainFrame());
@@ -56,7 +56,7 @@ public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request
   @Override
   public boolean shouldOverrideUrlLoading(WebView view, String url) {
     if (!hasNavigationDelegate) {
-      return super.shouldOverrideUrlLoading(view, url);
+      return false;
     }
     // This version of shouldOverrideUrlLoading is only invoked by the webview on devices with
     // webview versions  earlier than 67(it is also invoked when hasNavigationDelegate is false).