Handle NOT_SUPPORTED modem response as not supporting secondary carrier.

Bug: 176240063
Test: make, treehugger
Change-Id: If9f11d263a45df4befbe93067e667b049baf713f
diff --git a/src/com/android/phone/PhoneInterfaceManager.java b/src/com/android/phone/PhoneInterfaceManager.java
index 339c8a7..54a88fc 100755
--- a/src/com/android/phone/PhoneInterfaceManager.java
+++ b/src/com/android/phone/PhoneInterfaceManager.java
@@ -9779,7 +9779,9 @@
                 throw new IllegalArgumentException("modem returned INVALID_ARGUMENTS");
             } else if (thermalMitigationResult
                     == MODEM_DOES_NOT_SUPPORT_DATA_THROTTLING_ERROR_CODE) {
-                throw new IllegalArgumentException("modem does not support data throttling");
+                log("Modem likely does not support data throttling on secondary carrier. Data " +
+                        "throttling action = " + dataThrottlingRequest.getDataThrottlingAction());
+                return TelephonyManager.THERMAL_MITIGATION_RESULT_MODEM_ERROR;
             }
             return thermalMitigationResult;
         }