Hi Satish,
Did you change the schema name ? if no, as your original posted message, this schema has been created by .hdbschema.
I think that you cannot change icon of this object, it will be auto-completed by you activated action.
Could you refresh your project explorer and restart HANA studio? if it has same issue, please check out again this file from repository.
Hope this can help you.
Regards,
Jerry