Incorrect IDX/Firebase Studio template causing build errors

[domingoshawn]

Description: Due to recent refactoring of Google Maps SDK for Android sample apps, it now requires you to open the application at the top-level directory and build the gradle. This means that the subDir parameter is no longer required to build the application.

Currently, the IDX/Firebase Studio template defaults to "tutorials/java/MapWithMarker/" when subDir parameter is empty.

Fix: Remove the default parameter for subDir parameter from open-in-idx-template/idx-template.json

Current Workaround: Manually remove the "Project Subfolder" value in the Firebase Studio interface before creating the workspace. This adds additional step that is not documented and is not great for user experience especially for those unfamiliar with the environment.