It is absolutely possible. Here is a file with the instrument in question as well as an importable kit. What you need is to load the instrument "Drum Set (basic) in setup mode. Click the three dots beside the green kit that appears once you open the player card. Then choose “edit instrument definition”, click on the + icon at bottom left of that window, click “edit kit” remove all instruments except crash cymbal (it’s “out of kit” icon at bottom left, with an arrow out of a box), add Bass drum (plus icon), move the two instruments on either side of the center line, make sure that the bass drum is set to downstem, select cymbals and click 'edit playing technique, set the notehead to “larger notehead”, click OK, go down to Number of staff lines, scroll it down to 1, rename the instrument and save. Go to the instrument picker and select your new instrument (you may still have to rename it after that). But at any rate, here’s the file and the kit!
Rename Pump-Kit to Pump-Kit.doricolib
and
Rename Pump-File to Pump-File.dorico
Pump-Kit.zip (19.5 KB)
Pump.dorico (496.4 KB)