Change the Launch Screen to use System Background Color (#5608)
Change the Launch Screen to use System Background Color (#5608)

* Change the Launch Screen to use System Background Color as the background color, so that people in dark mode aren't blinded when they open the app (forces a darker background instead of white)

* Clean up LaunchScreen.xib to only change the systemBackgroundColor item

st3fan/firefox-ios,AaronMT/firefox-ios,Acidburn0zzz/firefox-ios,flodolo/firefox-ios,AaronMT/firefox-ios,mkaply/firefox-ios,st3fan/firefox-ios,mozilla-mobile/firefox-ios,flodolo/firefox-ios,st3fan/firefox-ios,st3fan/firefox-ios,AaronMT/firefox-ios,StYaphet/firefox-ios,garvankeeley/firefox-ios,mkaply/firefox-ios,st3fan/firefox-ios,mkaply/firefox-ios,StYaphet/firefox-ios,Acidburn0zzz/firefox-ios,garvankeeley/firefox-ios,AaronMT/firefox-ios,StYaphet/firefox-ios,st3fan/firefox-ios,flodolo/firefox-ios,garvankeeley/firefox-ios,garvankeeley/firefox-ios,StYaphet/firefox-ios,garvankeeley/firefox-ios,flodolo/firefox-ios,Acidburn0zzz/firefox-ios,StYaphet/firefox-ios,StYaphet/firefox-ios,flodolo/firefox-ios,Acidburn0zzz/firefox-ios,mozilla-mobile/firefox-ios,garvankeeley/firefox-ios,garvankeeley/firefox-ios,mozilla-mobile/firefox-ios,flodolo/firefox-ios,mozilla-mobile/firefox-ios,flodolo/firefox-ios,mkaply/firefox-ios,mozilla-mobile/firefox-ios,AaronMT/firefox-ios,Acidburn0zzz/firefox-ios,AaronMT/firefox-ios,StYaphet/firefox-ios,mkaply/firefox-ios,mozilla-mobile/firefox-ios,AaronMT/firefox-ios,Acidburn0zzz/firefox-ios,StYaphet/firefox-ios,st3fan/firefox-ios,mozilla-mobile/firefox-ios,st3fan/firefox-ios,mkaply/firefox-ios,mkaply/firefox-ios,Acidburn0zzz/firefox-ios,Acidburn0zzz/firefox-ios