shill: cellular: Fix CellularCapabilityUniversalCDMA::IsRegistered().

A CDMA modem may register on a network but fail to determine the roaming
status. ModemManager reports the CDMA (1xRTT/EVDO) registeration state
as MM_MODEM_CDMA_REGISTRATION_STATE_REGISTERED. This CL fixes
CellularCapabilityUniversalCDMA::IsRegistered() to include
MM_MODEM_CDMA_REGISTRATION_STATE_REGISTERED as a 'registered' state.
Otherwise, shill does not create a cellular service in such a scenario.

BUG=chromium:319496
TEST=Tested the following:
1. Build and run unit tests.
2. Verify that shill creates a cellular service for a CDMA dongle (e.g.
   ZTE AC2738) that registers on a CDMA network but fails to determine
   the roaming status.
3. Verify that shill creates a cellular service for a CDMA dongle (e.g.
   Huawei E1561) that registers on a CDMA network and reports the
   registeration status as 'home'.

Change-Id: I8b8d616a1965e237606aedef5c5bdce590f5fdaa
Reviewed-on: https://chromium-review.googlesource.com/176871
Reviewed-by: Thieu Le <thieule@chromium.org>
Tested-by: Ben Chan <benchan@chromium.org>
Commit-Queue: Ben Chan <benchan@chromium.org>
diff --git a/cellular_capability_universal_cdma.cc b/cellular_capability_universal_cdma.cc
index a1a4ecc..0e5d612 100644
--- a/cellular_capability_universal_cdma.cc
+++ b/cellular_capability_universal_cdma.cc
@@ -464,14 +464,10 @@
 }
 
 bool CellularCapabilityUniversalCDMA::IsRegistered() {
-  return (cdma_1x_registration_state_ ==
-              MM_MODEM_CDMA_REGISTRATION_STATE_HOME ||
-          cdma_1x_registration_state_ ==
-              MM_MODEM_CDMA_REGISTRATION_STATE_ROAMING ||
-          cdma_evdo_registration_state_ ==
-              MM_MODEM_CDMA_REGISTRATION_STATE_HOME ||
-          cdma_evdo_registration_state_ ==
-              MM_MODEM_CDMA_REGISTRATION_STATE_ROAMING);
+  return (cdma_1x_registration_state_ !=
+              MM_MODEM_CDMA_REGISTRATION_STATE_UNKNOWN ||
+          cdma_evdo_registration_state_ !=
+              MM_MODEM_CDMA_REGISTRATION_STATE_UNKNOWN);
 }
 
 void CellularCapabilityUniversalCDMA::SetUnregistered(bool /*searching*/) {