shill: cellular: Enable out-of-credits detection for ALT3100 modem.

BUG=chrome-os-partner:21739
TEST=Tested the following:
1. Build and run unit tests.
2. Verify that an out-of-credits notification is shown when the SIM on
   an ALT3100 modem runs out of data allowance.

Change-Id: Id6a89c672dbdad196457eb0209c8e1aa95f9a90e
Reviewed-on: https://gerrit.chromium.org/gerrit/65102
Commit-Queue: Ben Chan <benchan@chromium.org>
Reviewed-by: Ben Chan <benchan@chromium.org>
Tested-by: Ben Chan <benchan@chromium.org>
diff --git a/cellular_capability_universal.cc b/cellular_capability_universal.cc
index 887c94f..68b9b5a 100644
--- a/cellular_capability_universal.cc
+++ b/cellular_capability_universal.cc
@@ -69,6 +69,7 @@
 const char CellularCapabilityUniversal::kOperatorAccessTechnologyProperty[] =
     "access-technology";
 const char CellularCapabilityUniversal::kIpConfigPropertyMethod[] = "method";
+const char CellularCapabilityUniversal::kALT3100ModelId[] = "ALT3100";
 const char CellularCapabilityUniversal::kE362ModelId[] = "E362 WWAN";
 const int CellularCapabilityUniversal::kSetPowerStateTimeoutMilliseconds =
     20000;
@@ -728,9 +729,11 @@
   // WORKAROUND:
   // E362 modems on Verizon network does not properly redirect when a SIM
   // runs out of credits, we need to enforce out-of-credits detection.
-  // TODO(thieule): Remove this workaround (crosbug.com/p/18619).
-  if (model_id_ == kE362ModelId)
-    cellular()->service()->set_enforce_out_of_credits_detection(true);
+  //
+  // The out-of-credits detection is also needed on ALT3100 modems until the PCO
+  // support is ready (crosbug.com/p/20461).
+  cellular()->service()->set_enforce_out_of_credits_detection(
+      ShouldDetectOutOfCredit());
 
   // Make sure that the network technology is set when the service gets
   // created, just in case.
@@ -837,7 +840,7 @@
 }
 
 bool CellularCapabilityUniversal::ShouldDetectOutOfCredit() const {
-  return model_id_ == kE362ModelId;
+  return model_id_ == kALT3100ModelId || model_id_ == kE362ModelId;
 }
 
 void CellularCapabilityUniversal::GetProperties() {