Block connections without VPN doesn't work

[ignoramous]

"Always-on VPN" comes with a setting that lets users decide if any app should ever bypass the VPN to connect to the Internet... and that doesn't work with BraveDNS.

Figure out why and fix it. This might be important for folks who absolutely never want the Firewalled apps / DNS to ever bleed (despite app crashes).

See also: #91 #25 #23 #83

[ignoramous]

VpnService.Builder#allowBypass call is the culprit here. Check if VpnService#isLockdownMode is enabled and if so do not allowBypass ignoring this user-setting: #33

For a background on why allowBypass was required in the first-place, see: julian-klode/dns66#193 and Jigsaw-Code/Intra#18