Don't attempt shutting down adb on exit if not started

Fixes #88864.

platform/android/export/export_plugin.cpp

@@ -416,7 +416,7 @@ void EditorExportPlatformAndroid::_check_for_changes_poll_thread(void *ud) {
 		}
 	}
 
-	if (EDITOR_GET("export/android/shutdown_adb_on_exit")) {
+	if (ea->has_runnable_preset.is_set() && EDITOR_GET("export/android/shutdown_adb_on_exit")) {
 		String adb = get_adb_path();
 		if (!FileAccess::exists(adb)) {
 			return; //adb not configured