Add app icon to native calling screen.

Signed-off-by: Ivan Sein <ivan@nextcloud.com>

VideoCalls/CallKitManager.m

@@ -48,6 +48,7 @@ NSString * const CallKitManagerDidChangeAudioMuteNotification   = @"CallKitManag
         configuration.maximumCallGroups = 1;
         configuration.maximumCallsPerCallGroup = 1;
         configuration.supportedHandleTypes = [NSSet setWithObjects:@(CXHandleTypePhoneNumber), @(CXHandleTypeEmailAddress), @(CXHandleTypeGeneric), nil];
+        configuration.iconTemplateImageData = UIImagePNGRepresentation([UIImage imageNamed:@"app-logo-callkit"]);
         _provider = [[CXProvider alloc] initWithConfiguration:configuration];
         [_provider setDelegate:self queue:nil];
     }

VideoCalls/Images.xcassets/app-logo-callkit.imageset/Contents.json

@@ -0,0 +1,23 @@
+{
+  "images" : [
+    {
+      "idiom" : "universal",
+      "filename" : "app-logo-callkit.png",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "universal",
+      "filename" : "app-logo-callkit@2x.png",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "universal",
+      "filename" : "app-logo-callkit@3x.png",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}