Android用のWebViewを追加。OSのブラウザは起動できないため。

pubspec.lock

@@ -1389,6 +1389,38 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "0.5.1"
+  webview_flutter:
+    dependency: "direct main"
+    description:
+      name: webview_flutter
+      sha256: "392c1d83b70fe2495de3ea2c84531268d5b8de2de3f01086a53334d8b6030a88"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.0.4"
+  webview_flutter_android:
+    dependency: transitive
+    description:
+      name: webview_flutter_android
+      sha256: "8b3b2450e98876c70bfcead876d9390573b34b9418c19e28168b74f6cb252dbd"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.10.4"
+  webview_flutter_platform_interface:
+    dependency: transitive
+    description:
+      name: webview_flutter_platform_interface
+      sha256: "812165e4e34ca677bdfbfa58c01e33b27fd03ab5fa75b70832d4b7d4ca1fa8cf"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.9.5"
+  webview_flutter_wkwebview:
+    dependency: transitive
+    description:
+      name: webview_flutter_wkwebview
+      sha256: a5364369c758892aa487cbf59ea41d9edd10f9d9baf06a94e80f1bd1b4c7bbc0
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.9.5"
   win32:
     dependency: transitive
     description: