shouldOverrideUrlLoading always returns true for HTTP/HTTPS URLs, destroying browsing context (window.opener, Referer, Sec-Fetch-Site)

### Is there an existing issue for this? - [x] I have searched the existing issues ### Current Behavior The plugin's Java-side shouldOverrideUrlLoading() always returns true for all URLs (including HTTP/HTTPS) when useShouldOverrideUrlLoading is enabled. This immediately cancels the original navigation. When the Dart side returns NavigationActionPolicy.ALLOW, the allowShouldOverrideUrlLoading() method calls webView.loadUrl(url) to start a completely new navigation that has lost all browsing context: window.opener becomes null Referer header is missing Sec-Fetch-Site becomes none instead of cross-site or same-origin Sec-Fetch-Dest may change Any opener–popup JavaScript relationship is severed This breaks real-world payment flows (e.g., PAYCO, Kakao Pay) that rely on window.opener to communicate between popup and parent windows. ### Expected Behavior When useShouldOverrideUrlLoading is enabled and the Dart callback returns NavigationActionPolicy.ALLOW for an HTTP/HTTPS URL, the navigation should proceed as if the plugin never intercepted it — preserving the original browsing context including window.opener, Referer header, and Sec-Fetch-Site header. This is consistent with how native Android apps handle shouldOverrideUrlLoading: return false for HTTP/HTTPS URLs to let the WebView engine process them natively. ### Steps with code example to reproduce <details> //In both InAppWebViewClient.java (line 93/112) and InAppWebViewClientCompat.java (line 101/124): // InAppWebViewClient.java — shouldOverrideUrlLoading (API 21+) @Override public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) { InAppWebView webView = (InAppWebView) view; if (webView.customSettings.useShouldOverrideUrlLoading) { onShouldOverrideUrlLoading(webView, ...); // ... return true; // <-- ALWAYS true, even for http/https } return false; } </details> ### Stacktrace/Logs <details> Before navigation in popup — opener exists D/PopupWebView: opener check: {"url":"https://example.com/popup","openerType":"object","openerIsNull":false,"openerValue":"[object Window]"} // shouldOverrideUrlLoading fires for an HTTP navigation D/PopupWebView: shouldOverrideUrlLoading called: https://payment-gateway.com/checkout // After navigation completes (loadUrl was called internally) — opener is gone D/PopupWebView: opener check: {"url":"https://payment-gateway.com/checkout","openerType":"object","openerIsNull":true,"openerValue":"null"} ``` </details> ### Flutter version flutter_inappwebview: 6.1.5 flutter_inappwebview_android: 1.1.3 ### Operating System, Device-specific and/or Tool Android inappwebview Even returning ALLOW for http/https causes the issue makes me shouldOverrideUrlLoading Options like android native InAppWebView( initialUrlRequest: URLRequest(url: WebUri('https://example.com/parent')), initialSettings: InAppWebViewSettings( javaScriptEnabled: true, javaScriptCanOpenWindowsAutomatically: true, supportMultipleWindows: true, useShouldOverrideUrlLoading: true, // <-- this triggers the bug ), shouldOverrideUrlLoading: (controller, navigationAction) async { // Even returning ALLOW for http/https causes the issue return NavigationActionPolicy.ALLOW; }, onCreateWindow: (controller, createWindowAction) async { // Open popup with windowId to preserve opener relationship Navigator.push(context, MaterialPageRoute( builder: (context) => Scaffold( body: InAppWebView( windowId: createWindowAction.windowId, initialSettings: InAppWebViewSettings( javaScriptEnabled: true, useShouldOverrideUrlLoading: true, ), shouldOverrideUrlLoading: (controller, navigationAction) async { return NavigationActionPolicy.ALLOW; }, ), ), )); return true; }, ); // android native return shouldOverridUrlLoading as boolean. override fun shouldOverrideUrlLoading( view: WebView?, request: WebResourceRequest? ): Boolean { } ### Plugin version flutter_inappwebview: 6.1.5 flutter_inappwebview_android: 1.1.3 ### Additional information _No response_ ### Self grab - [x] I'm ready to work on this issue!