tests: Replace is_connected() with is_registered()

API was renamed and old name deprecated, let's use it everywhere.

Change-Id: Ic91dddcfd1a5a17c35d15a8a14628b3923229523
diff --git a/src/osmo_gsm_tester/obj/ms_ofono.py b/src/osmo_gsm_tester/obj/ms_ofono.py
index e03427e..cec6824 100644
--- a/src/osmo_gsm_tester/obj/ms_ofono.py
+++ b/src/osmo_gsm_tester/obj/ms_ofono.py
@@ -519,10 +519,6 @@
             return True
         return False
 
-    def is_connected(self, mcc_mnc=None):
-        '''Convenience helper to keep old test API'''
-        return self.is_registered(mcc_mnc)
-
     def schedule_scan_register(self, mcc_mnc):
         if self.register_attempts > NETREG_MAX_REGISTER_ATTEMPTS:
             raise log.Error('Failed to find Network Operator', mcc_mnc=mcc_mnc, attempts=self.register_attempts)
@@ -547,7 +543,7 @@
         # So far the easiest seems to check if we are now registered and
         # otherwise schedule a scan again.
         self.err('Scan() failed, retrying if needed:', e)
-        if not self.is_connected(mcc_mnc):
+        if not self.is_registered(mcc_mnc):
             self.schedule_scan_register(mcc_mnc)
         else:
             self.log('Already registered with network', mcc_mnc)
@@ -632,7 +628,7 @@
         self.cancel_pending_dbus_methods()
         self.power_cycle()
         self.register_attempts = 0
-        if self.is_connected(mcc_mnc):
+        if self.is_registered(mcc_mnc):
             self.log('Already registered with', mcc_mnc if mcc_mnc else 'default network')
         else:
             self.log('Connect to', mcc_mnc if mcc_mnc else 'default network')