[iOS] Add icon for CallKit in-call UI

ios/sdk/sdk.xcodeproj/project.pbxproj

 		0BA13D311EE83FF8007BEF7F /* ExternalAPI.m in Sources */ = {isa = PBXBuildFile; fileRef = 0BA13D301EE83FF8007BEF7F /* ExternalAPI.m */; };
 		0BB9AD7B1F5EC8F4001C08DB /* CallKit.m in Sources */ = {isa = PBXBuildFile; fileRef = 0BB9AD7A1F5EC8F4001C08DB /* CallKit.m */; };
 		0BB9AD7D1F60356D001C08DB /* AppInfo.m in Sources */ = {isa = PBXBuildFile; fileRef = 0BB9AD7C1F60356D001C08DB /* AppInfo.m */; };
+		0BC4B8691F8C03A700CE8B21 /* CallKitIcon.png in Resources */ = {isa = PBXBuildFile; fileRef = 0BC4B8681F8C01E100CE8B21 /* CallKitIcon.png */; };
 		0BCA495F1EC4B6C600B793EE /* AudioMode.m in Sources */ = {isa = PBXBuildFile; fileRef = 0BCA495C1EC4B6C600B793EE /* AudioMode.m */; };
 		0BCA49601EC4B6C600B793EE /* POSIX.m in Sources */ = {isa = PBXBuildFile; fileRef = 0BCA495D1EC4B6C600B793EE /* POSIX.m */; };
 		0BCA49611EC4B6C600B793EE /* Proximity.m in Sources */ = {isa = PBXBuildFile; fileRef = 0BCA495E1EC4B6C600B793EE /* Proximity.m */; };
 		0BA13D301EE83FF8007BEF7F /* ExternalAPI.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = ExternalAPI.m; sourceTree = "<group>"; };
 		0BB9AD7A1F5EC8F4001C08DB /* CallKit.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = CallKit.m; sourceTree = "<group>"; };
 		0BB9AD7C1F60356D001C08DB /* AppInfo.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = AppInfo.m; sourceTree = "<group>"; };
+		0BC4B8681F8C01E100CE8B21 /* CallKitIcon.png */ = {isa = PBXFileReference; lastKnownFileType = image.png; name = CallKitIcon.png; path = ../../react/features/mobile/callkit/CallKitIcon.png; sourceTree = "<group>"; };
 		0BCA495C1EC4B6C600B793EE /* AudioMode.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = AudioMode.m; sourceTree = "<group>"; };
 		0BCA495D1EC4B6C600B793EE /* POSIX.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = POSIX.m; sourceTree = "<group>"; };
 		0BCA495E1EC4B6C600B793EE /* Proximity.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = Proximity.m; sourceTree = "<group>"; };
 		0BCA49681EC4BBE500B793EE /* Resources */ = {
 			isa = PBXGroup;
 			children = (
+				0BC4B8681F8C01E100CE8B21 /* CallKitIcon.png */,
 				0BCA496B1EC4BBF900B793EE /* jitsi.ttf */,
 			);
 			name = Resources;
 			buildActionMask = 2147483647;
 			files = (
 				0BCA496C1EC4BBF900B793EE /* jitsi.ttf in Resources */,
+				0BC4B8691F8C03A700CE8B21 /* CallKitIcon.png in Resources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};

ios/sdk/src/CallKit.m

     // iconTemplateImageData
     NSString *iconTemplateImageName = dictionary[@"iconTemplateImageName"];
     if (iconTemplateImageName) {
-        UIImage *iconTemplateImage = [UIImage imageNamed:iconTemplateImageName];
+        UIImage *iconTemplateImage
+            = [UIImage imageNamed:iconTemplateImageName
+                         inBundle:[NSBundle bundleForClass:self.class]
+    compatibleWithTraitCollection:nil];
         if (iconTemplateImage) {
             providerConfiguration.iconTemplateImageData
                 = UIImagePNGRepresentation(iconTemplateImage);

react/features/mobile/callkit/middleware.js

     const result = next(action);
 
     CallKit.setProviderConfiguration({
-        iconTemplateImageName: 'AppIcon40x40',
+        iconTemplateImageName: 'CallKitIcon',
         localizedName: NativeModules.AppInfo.name
     });