PM-3349 Implemented HybridWebViewHandler for Android which enables 2nd factor auth flows

Ensured CustomTabbedPageHandler had it's DisconnectHandler called
Some minor code upgrades of older obsolete Xamarin Forms code.

src/App/Handlers/HybridWebViewHandler.cs

@@ -0,0 +1,25 @@
+#if IOS || MACCATALYST
+using PlatformView = WebKit.WKWebView;
+#elif ANDROID
+using PlatformView = Android.Webkit.WebView;
+#elif (NETSTANDARD || !PLATFORM) || (NET6_0_OR_GREATER && !IOS && !ANDROID)
+using PlatformView = System.Object;
+#endif
+
+using Bit.App.Controls;
+using Microsoft.Maui.Handlers;
+
+namespace Bit.App.Handlers
+{
+    public partial class HybridWebViewHandler
+    {
+        public static PropertyMapper<HybridWebView, HybridWebViewHandler> PropertyMapper = new PropertyMapper<HybridWebView, HybridWebViewHandler>(ViewHandler.ViewMapper)
+        {
+            [nameof(HybridWebView.Uri)] = MapUri
+        };
+
+        public HybridWebViewHandler() : base(PropertyMapper)
+        {
+        }
+    }
+}

src/App/MauiProgram.cs

@@ -1,4 +1,4 @@
-namespace Bit.App
+namespace Bit.App
 {
     public class MauiProgram
     {
@@ -28,7 +28,8 @@ namespace Bit.App
                     Bit.App.Handlers.TimePickerHandlerMappings.Setup();
                     Bit.App.Handlers.ButtonHandlerMappings.Setup();
 
-                    handlers.AddHandler(typeof(TabbedPage), typeof(Bit.App.Handlers.CustomTabbedPageHandler));
+                    handlers.AddHandler(typeof(Bit.App.Pages.TabsPage), typeof(Bit.App.Handlers.CustomTabbedPageHandler));
+                    handlers.AddHandler(typeof(Bit.App.Controls.HybridWebView), typeof(Bit.App.Handlers.HybridWebViewHandler));
 #else
                     iOS.Core.Utilities.iOSCoreHelpers.ConfigureMAUIHandlers(handlers);
 #endif

src/App/Platforms/Android/Handlers/CustomTabbedPageHandler.cs

@@ -1,5 +1,4 @@
 using AndroidX.AppCompat.View.Menu;
-using AndroidX.Navigation.UI;
 using Bit.Core.Abstractions;
 using Bit.Core.Utilities;
 using Google.Android.Material.BottomNavigation;
@@ -95,6 +94,7 @@ namespace Bit.App.Handlers
 			}
         }
 
+        //Currently the Disconnect Handler needs to be manually called from the App: https://github.com/dotnet/maui/issues/3604
         protected override void DisconnectHandler(global::Android.Views.View platformView) 
         {
             if(_bottomNavigationViewGroup != null)

src/App/Platforms/Android/Handlers/HybridWebViewHandler.cs

@@ -0,0 +1,96 @@
+using Bit.App.Controls;
+using Java.Interop;
+using JetBrains.Annotations;
+using Microsoft.Maui.Handlers;
+using AWebkit = Android.Webkit;
+
+namespace Bit.App.Handlers
+{
+    public partial class HybridWebViewHandler : ViewHandler<HybridWebView, AWebkit.WebView>
+    {
+        private const string JSFunction = "function invokeCSharpAction(data){jsBridge.invokeAction(data);}";
+
+        public HybridWebViewHandler([NotNull] IPropertyMapper mapper, CommandMapper commandMapper = null) : base(mapper, commandMapper)
+        {
+        }
+
+        protected override AWebkit.WebView CreatePlatformView()
+        {
+            var context = MauiContext?.Context ?? throw new InvalidOperationException($"Context cannot be null here");
+            var webView = new AWebkit.WebView(context);
+            webView.Settings.JavaScriptEnabled = true;
+            webView.SetWebViewClient(new JSWebViewClient(string.Format("javascript: {0}", JSFunction)));
+            return webView;
+        }
+
+        public static void MapUri(HybridWebViewHandler handler, HybridWebView view)
+        {
+            if (view != null && view.Uri != null)
+            {
+                handler?.PlatformView?.LoadUrl(view.Uri);
+            }
+        }
+
+        protected override void ConnectHandler(AWebkit.WebView platformView)
+        {
+            platformView?.AddJavascriptInterface(new JSBridge(this), "jsBridge");
+            platformView?.LoadUrl(VirtualView?.Uri);
+
+            base.ConnectHandler(platformView);
+        }
+
+        //Currently the Disconnect Handler needs to be manually called from the App: https://github.com/dotnet/maui/issues/3604
+        protected override void DisconnectHandler(AWebkit.WebView platformView)
+        {
+            platformView?.RemoveJavascriptInterface("jsBridge");
+            platformView?.Dispose();
+            VirtualView?.Cleanup();
+
+            base.DisconnectHandler(platformView);
+        }
+
+        internal void InvokeActionOnVirtual(string data)
+        {
+            VirtualView?.InvokeAction(data);
+        }
+    }
+
+    public class JSBridge : Java.Lang.Object
+    {
+        private readonly WeakReference<HybridWebViewHandler> _hybridWebViewRenderer;
+
+        public JSBridge(HybridWebViewHandler hybridRenderer)
+        {
+            _hybridWebViewRenderer = new WeakReference<HybridWebViewHandler>(hybridRenderer);
+        }
+
+        [AWebkit.JavascriptInterface]
+        [Export("invokeAction")]
+        public void InvokeAction(string data)
+        {
+            if (_hybridWebViewRenderer != null &&_hybridWebViewRenderer.TryGetTarget(out HybridWebViewHandler hybridRenderer))
+            {
+                hybridRenderer?.InvokeActionOnVirtual(data);
+            }
+        }
+    }
+
+    public class JSWebViewClient : AWebkit.WebViewClient
+    {
+        private readonly string _javascript;
+
+        public JSWebViewClient(string javascript)
+        {
+            _javascript = javascript;
+        }
+
+        public override void OnPageFinished(AWebkit.WebView view, string url)
+        {
+            base.OnPageFinished(view, url);
+            if (view != null)
+            {
+                view.EvaluateJavascript(_javascript, null);
+            }
+        }
+    }
+}