Make "Default (0)" the default `frame_mode` value
Make "Default (0)" the default `frame_mode` value

Initially, the default `frame_mode` was "Original (2)` because there seems to be a bug with "Default (0)."  Set the default value to the intended default, "Default (0)" in anticipation of fixing the bug.
uzh-rpg/rpg_dvs_ros,uzh-rpg/rpg_dvs_ros,uzh-rpg/rpg_dvs_ros