fix(devtools-ios): Ensure UI modifications run on main thread

Modifications to the UI can only be made from the main thread.
Since {N} 5.3.0 all debugger protocol messages are processed
by the worker thread that receives them in iOS.

refs #7219, https://github.com/NativeScript/ios-runtime/pull/1101

tns-core-modules/utils/utils.android.ts

@@ -372,3 +372,14 @@ Please ensure you have your manifest correctly configured with the FileProvider.
         return false;
     }
 }
+
+export function executeOnMainThread(func: () => void) {
+    new android.os.Handler(android.os.Looper.getMainLooper())
+        .post(new java.lang.Runnable({
+            run: func
+        }));
+}
+
+export function isMainThread(): Boolean {
+    return android.os.Looper.myLooper() === android.os.Looper.getMainLooper();
+}