...'com::sun::star::sheet::XSpreadsheets2::importSheet', previous versions of
the compiler did not override when parameters only differed by const/volatile
qualifiers.

XSpreadsheets2.hdl defines this as:

virtual ::sal_Int32 SAL_CALL importSheet( const ::css::uno::Reference< ::css::sheet::XSpreadsheetDocument >& srcDoc, const ::rtl::OUString& srcName, ::sal_Int32 nDestPosition )

Change-Id: I286fa542a2124a85d7b835f257865f8a05c23f96