Clear intent from autofill. Background app when back button on lock page.

src/App/Pages/Lock/BaseLockPage.cs

@@ -0,0 +1,41 @@
+using System.Threading.Tasks;
+using Acr.UserDialogs;
+using Bit.App.Controls;
+using Bit.App.Resources;
+using Xamarin.Forms;
+using XLabs.Ioc;
+
+namespace Bit.App.Pages
+{
+    public class BaseLockPage : ExtendedContentPage
+    {
+        public BaseLockPage()
+            : base(false, false)
+        {
+
+            UserDialogs = Resolver.Resolve<IUserDialogs>();
+        }
+
+        protected IUserDialogs UserDialogs { get; set; }
+
+        protected override bool OnBackButtonPressed()
+        {
+            if(Device.OS == TargetPlatform.Android)
+            {
+                MessagingCenter.Send(Application.Current, "BackgroundApp");
+            }
+
+            return true;
+        }
+
+        protected async Task LogoutAsync()
+        {
+            if(!await UserDialogs.ConfirmAsync(AppResources.LogoutConfirmation, null, AppResources.Yes, AppResources.Cancel))
+            {
+                return;
+            }
+
+            MessagingCenter.Send(Application.Current, "Logout", (string)null);
+        }
+    }
+}