app icon in CallKit screen (#2003)

apps/ios/Shared/Assets.xcassets/icon-transparent.imageset/Contents.json

@@ -0,0 +1,23 @@
+{
+  "images" : [
+    {
+      "filename" : "60.png",
+      "idiom" : "universal",
+      "scale" : "1x"
+    },
+    {
+      "filename" : "120.png",
+      "idiom" : "universal",
+      "scale" : "2x"
+    },
+    {
+      "filename" : "180.png",
+      "idiom" : "universal",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}

apps/ios/Shared/Views/Call/CallController.swift

@@ -26,6 +26,7 @@ class CallController: NSObject, CXProviderDelegate, PKPushRegistryDelegate, Obse
         configuration.includesCallsInRecents = UserDefaults.standard.bool(forKey: DEFAULT_CALL_KIT_CALLS_IN_RECENTS)
         configuration.maximumCallGroups = 1
         configuration.maximumCallsPerCallGroup = 1
+        configuration.iconTemplateImageData = UIImage(named: "icon-transparent")?.pngData()
         return configuration
     }())
     private let controller = CXCallController()