Cleanup flag add_anomaly_when_notify_config_changed_with_invalid_phone

The flag has been advanced to next for a while and there is no
regression observed. Clean the flag to keep code healthy.

Bug: 270757342
Test: m -j
Flag: EXEMPT aconfig flag clean up only
Change-Id: I80797c5971dd159bffe10ed4cc4309600d0ed52e
diff --git a/src/com/android/phone/CarrierConfigLoader.java b/src/com/android/phone/CarrierConfigLoader.java
index 7f720c2..46f20f5 100644
--- a/src/com/android/phone/CarrierConfigLoader.java
+++ b/src/com/android/phone/CarrierConfigLoader.java
@@ -1497,10 +1497,8 @@
         if (!SubscriptionManager.isValidPhoneId(phoneId)) {
             final String msg =
                     "Ignore invalid phoneId: " + phoneId + " for subId: " + subscriptionId;
-            if (mFeatureFlags.addAnomalyWhenNotifyConfigChangedWithInvalidPhone()) {
-                AnomalyReporter.reportAnomaly(
-                        UUID.fromString(UUID_NOTIFY_CONFIG_CHANGED_WITH_INVALID_PHONE), msg);
-            }
+            AnomalyReporter.reportAnomaly(
+                    UUID.fromString(UUID_NOTIFY_CONFIG_CHANGED_WITH_INVALID_PHONE), msg);
             logd(msg);
             throw new IllegalArgumentException(msg);
         }