Remove second box-shadow attribute, add as a 3rd item (in a comma separated list)
Remove second box-shadow attribute, add as a 3rd item (in a comma
separated list)

Fixes https://github.com/brave/browser-laptop/issues/4309

Auditors: b664134269e58811b44b6762faa77742e9c9d1a7@srirambv

pmkary/braver,dcposch/browser-laptop,timborden/browser-laptop,darkdh/browser-laptop,Sh1d0w/browser-laptop,jonathansampson/browser-laptop,diasdavid/browser-laptop,luixxiul/browser-laptop,luixxiul/browser-laptop,jonathansampson/browser-laptop,luixxiul/browser-laptop,willy-b/browser-laptop,dcposch/browser-laptop,luixxiul/browser-laptop,pmkary/braver,darkdh/browser-laptop,dcposch/browser-laptop,jonathansampson/browser-laptop,darkdh/browser-laptop,pmkary/braver,diasdavid/browser-laptop,Sh1d0w/browser-laptop,darkdh/browser-laptop,timborden/browser-laptop,Sh1d0w/browser-laptop,timborden/browser-laptop,Sh1d0w/browser-laptop,timborden/browser-laptop,jonathansampson/browser-laptop,dcposch/browser-laptop,diasdavid/browser-laptop,willy-b/browser-laptop,diasdavid/browser-laptop,willy-b/browser-laptop,willy-b/browser-laptop,pmkary/braver