D-Bus API based peripheral need guidance on setting Advertising_Interval_Min and Advertising_Interval_Max

I have a BLE peripheral running on top of Raspbian Buster, Kernel version 4.19 and BlueZ v 5.50.  I need to set the advertising interval from the default 1.2 seconds to a much more aggressive setting say 200mS.  Can someone please give my guidance on the best way to achieve this.   The only way I can find to do this is to completely setup my advertising packet with the HCI tool.  I have to be missing something. Is there a way to simply change the default advertising interval?

Thanks
JR