new carrier id API

1. new APIs to getCurrentCarrierId and getCurrentCarrierName
2. new broadcast intent to notify carrier id changed
3. remove unused imports

Bug: 64131637
Test: Build
Change-Id: I3f3ca2eb2c70a50386b1cc626b6b775c1449a4e3
diff --git a/src/com/android/phone/PhoneInterfaceManager.java b/src/com/android/phone/PhoneInterfaceManager.java
index d199100..464f6cb 100644
--- a/src/com/android/phone/PhoneInterfaceManager.java
+++ b/src/com/android/phone/PhoneInterfaceManager.java
@@ -39,7 +39,6 @@
 import android.os.Message;
 import android.os.Messenger;
 import android.os.PersistableBundle;
-import android.os.Process;
 import android.os.ResultReceiver;
 import android.os.ServiceManager;
 import android.os.UserHandle;
@@ -1770,6 +1769,18 @@
       return phone == null ? null : phone.getDeviceSvn();
     }
 
+    @Override
+    public int getSubscriptionCarrierId(int subId) {
+        final Phone phone = getPhone(subId);
+        return phone == null ? TelephonyManager.UNKNOWN_CARRIER_ID : phone.getCarrierId();
+    }
+
+    @Override
+    public String getSubscriptionCarrierName(int subId) {
+        final Phone phone = getPhone(subId);
+        return phone == null ? null : phone.getCarrierName();
+    }
+
     //
     // Internal helper methods.
     //