[PS-1312] Migration to android12 and new splashscreen (#2063)

* [PS-1312] Updated Android Target and Framework to Android12 and updated new SplashScreen for Android12

* PS-1312 Changed PendingIntents mutability

* PS-1312 Removed unused imports

* PS-1312 Added method to helper to add mutability option according to Android version

* PS-1312 Renamed helper method AddPendingIntentMutability and fixed validation

* PS-1312 Improved PendingIntentMutability method from helper readability and naming

src/Android/Services/ClipboardService.cs

@@ -5,6 +5,7 @@ using Android.Content;
 using Android.OS;
 using Bit.Core.Abstractions;
 using Bit.Droid.Receivers;
+using Bit.Droid.Utilities;
 using Plugin.CurrentActivity;
 using Xamarin.Essentials;
 
@@ -23,7 +24,7 @@ namespace Bit.Droid.Services
                 PendingIntent.GetBroadcast(CrossCurrentActivity.Current.Activity,
                                            0,
                                            new Intent(CrossCurrentActivity.Current.Activity, typeof(ClearClipboardAlarmReceiver)),
-                                           PendingIntentFlags.UpdateCurrent));
+                                           AndroidHelpers.AddPendingIntentMutabilityFlag(PendingIntentFlags.UpdateCurrent, false)));
         }
 
         public async Task CopyTextAsync(string text, int expiresInMs = -1, bool isSensitive = true)