Review Mozilla 1899182: Turn on the preference `media.eme.encrypted-media-encryption-scheme.enable` b...

Bugzilla: https://bugzilla.mozilla.org/show_bug.cgi?id=1899182

Seems to be related to EME (Encrypted Media Extensions) and seems to add encryptionScheme to the requestMediaKeySystemAccess API. I would guess this is already handled by existing resist fingerprinting measures, but I'm not sure.