fix(pbxproj): Fix compat with some plugins

Some plugins look up the root group of the Xcode project based on the
name "CustomTemplate", which isn't really an ideal thing to do but I'm
unsure if there are better options and this name doesn't actually get
displayed anywhere so we might as well keep the label for compatibility
reasons.

templates/project/App.xcodeproj/project.pbxproj

@@ -128,7 +128,7 @@
 			name = staging;
 			sourceTree = "<group>";
 		};
-		90BD9B632C06907D000DEBAB = {
+		90BD9B632C06907D000DEBAB /* CustomTemplate */ = {
 			isa = PBXGroup;
 			children = (
 				9080B40F2C6DD7EC00078F33 /* config.xml */,
@@ -137,6 +137,7 @@
 				90BD9B6D2C06907D000DEBAB /* Products */,
 				907F98602C06B8F000D2D242 /* Frameworks */,
 			);
+			name = CustomTemplate;
 			sourceTree = "<group>";
 		};
 		90BD9B6D2C06907D000DEBAB /* Products */ = {
@@ -218,7 +219,7 @@
 				en,
 				Base,
 			);
-			mainGroup = 90BD9B632C06907D000DEBAB;
+			mainGroup = 90BD9B632C06907D000DEBAB /* CustomTemplate */;
 			packageReferences = (
 				90A914572CA3D370003DB979 /* XCLocalSwiftPackageReference "../../../cordova-ios" */,
 			);