lock page fixes

src/App/Pages/Accounts/LockPage.xaml.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Threading.Tasks;
 using Xamarin.Forms;
 
 namespace Bit.App.Pages
@@ -33,11 +34,18 @@ namespace Bit.App.Pages
             }
         }
 
-        private async void Unlock_Clicked(object sender, EventArgs e)
+        private void Unlock_Clicked(object sender, EventArgs e)
         {
             if(DoOnce())
             {
-                await _vm.SubmitAsync();
+                var tasks = Task.Run(async () =>
+                {
+                    await Task.Delay(50);
+                    Device.BeginInvokeOnMainThread(async () =>
+                    {
+                        await _vm.SubmitAsync();
+                    });
+                });
             }
         }
 

src/App/Pages/Accounts/LockPageViewModel.cs

@@ -169,6 +169,7 @@ namespace Bit.App.Pages
         private async Task SetKeyAndContinueAsync(SymmetricCryptoKey key)
         {
             await _cryptoService.SetKeyAsync(key);
+            DoContinue();
         }
 
         private void DoContinue()

src/App/Resources/AppResources.Designer.cs

@@ -3498,6 +3498,15 @@ namespace Bit.App.Resources {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Unlock.
+        /// </summary>
+        public static string Unlock {
+            get {
+                return ResourceManager.GetString("Unlock", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Unlock with {0}.
         /// </summary>

src/App/Resources/AppResources.resx

@@ -1487,4 +1487,7 @@
   <data name="PIN" xml:space="preserve">
     <value>PIN</value>
   </data>
+  <data name="Unlock" xml:space="preserve">
+    <value>Unlock</value>
+  </data>
 </root>

src/Core/Services/CryptoService.cs

@@ -99,7 +99,7 @@ namespace Bit.Core.Services
             {
                 _key = new SymmetricCryptoKey(Convert.FromBase64String(key));
             }
-            return key == null ? null : _key;
+            return _key;
         }
 
         public async Task<string> GetKeyHashAsync()
@@ -108,12 +108,12 @@ namespace Bit.Core.Services
             {
                 return _keyHash;
             }
-            var keyHash = await _secureStorageService.GetAsync<string>(Keys_KeyHash);
+            var keyHash = await _storageService.GetAsync<string>(Keys_KeyHash);
             if(keyHash != null)
             {
                 _keyHash = keyHash;
             }
-            return keyHash == null ? null : _keyHash;
+            return _keyHash;
         }
 
         public Task<SymmetricCryptoKey> GetEncKeyAsync()