The only thing that doesn't work yet is the system-settings service's
"auto eth" connections for ethernet devices that don't have an existing
connection. Might also have issues with unmanaged devices that can't
provide a MAC address until they are brought up, but we'll see.
Fixes a bug where if GSM secrets were required, the connection would fail
because they were requested with SECRETS_CALLER_HSO_GSM, but the function
to handle retrieved secrets only expected SECRETS_CALLER_GSM.
