add flash sitehack on ESPN.com
add flash sitehack on ESPN.com

fix https://github.com/brave/browser-laptop/issues/4572

Auditors: @luixxiul

Test Plan:
1. enable flash
2. go to espn.com
3. flash bar should appear. click 'allow'
4. videos on espn.com should play

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