In auto brim mode, first layer of common support may be apart from object island, which is controled by support object distance.
if support object distance is lower than "flow width + brim_object_gap", the brim will not work.
Therefore, if first layer of common support is interesected with object island, the distance will be brim_object_gap in auto brim mode.
Change-Id: Icbb98af8fd9e84e3ac1977794ca2b60629dd53dd