Managed Mode Updates #20
Description
Right now the managed mode is a protobufs only config option that is honored by the two phone clients.
- Allow updating of managed mode devices only over the admin channel, disable serial and phone api configuration changes.
- Client apps should check for an admin channel or shared key before enabling managed mode.
- Direct users to use the web flasher to wipe a device if they get into managed mode if they get stuck and can't turn it off.