Test debug

```
[E] [ERROR:flutter/runtime/dart_vm_initializer.cc(41)] Unhandled Exception: PlatformException(Invalid operation, The webview instance has not been initialized.
 Fail to create ecore evas.
 Fail to create ewk_view., null, null)
 #0      StandardMethodCodec.decodeEnvelope (package:flutter/src/services/message_codecs.dart:651)
 #1      MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:322)
<asynchronous suspension>

```

packages/webview_flutter/tizen/src/webview.cc

@@ -297,9 +297,15 @@ void WebView::InitWebView() {
                                                          chromium_argv);
 
   ewk_init();
-  Ecore_Evas* evas = ecore_evas_new("wayland_egl", 0, 0, 1, 1, 0);
+  Ecore_Evas* evas = nullptr;  // ecore_evas_new("wayland_egl", 0, 0, 1, 1, 0);
+  if (!evas) {
+    debug_log_ += "\n Fail to create ecore evas.";
+  }
 
-  webview_instance_ = ewk_view_add(ecore_evas_get(evas));
+  webview_instance_ = nullptr;  // ewk_view_add(ecore_evas_get(evas));
+  if (!webview_instance_) {
+    debug_log_ += "\n Fail to create ewk_view.";
+  }
   ecore_evas_focus_set(evas, true);
   ewk_view_focus_set(webview_instance_, true);
   EwkInternalApiBinding::GetInstance().view.OffscreenRenderingEnabledSet(
@@ -351,8 +357,9 @@ void WebView::InitWebView() {
 void WebView::HandleWebViewMethodCall(const FlMethodCall& method_call,
                                       std::unique_ptr<FlMethodResult> result) {
   if (!webview_instance_) {
-    result->Error("Invalid operation",
-                  "The webview instance has not been initialized.");
+    result->Error(
+        "Invalid operation",
+        "The webview instance has not been initialized.\n" + debug_log_);
     return;
   }
 

packages/webview_flutter/tizen/src/webview.h

@@ -99,6 +99,8 @@ class WebView : public PlatformView {
   std::unique_ptr<flutter::TextureVariant> texture_variant_;
   std::mutex mutex_;
   std::unique_ptr<BufferPool> tbm_pool_;
+
+  std::string debug_log_;
 };
 
 #endif  // FLUTTER_PLUGIN_WEBVIEW_H_