New System Api: getGroupIdLevel2

- add new flag

Bug: b/381171540
Test: atest
FLAG: com.android.internal.telephony.flags.get_group_id_level2
Change-Id: Ie49c055747f6e5e9f676ba0afe9f31700868b8ba
diff --git a/flags/uicc.aconfig b/flags/uicc.aconfig
index aed4bff..d97f397 100644
--- a/flags/uicc.aconfig
+++ b/flags/uicc.aconfig
@@ -107,3 +107,11 @@
         purpose: PURPOSE_BUGFIX
     }
 }
+
+# OWNER=jinjeong TARGET=25Q2
+flag {
+    name: "get_group_id_level2"
+    namespace: "telephony"
+    description: "This flag controls to get a group id level2."
+    bug:"381171540"
+}
diff --git a/src/java/com/android/internal/telephony/PhoneSubInfoController.java b/src/java/com/android/internal/telephony/PhoneSubInfoController.java
index c40193e..9801542 100644
--- a/src/java/com/android/internal/telephony/PhoneSubInfoController.java
+++ b/src/java/com/android/internal/telephony/PhoneSubInfoController.java
@@ -659,6 +659,20 @@
                 });
     }
 
+    /**
+     * Return GroupIdLevel2 for the subscriber
+     */
+    public String getGroupIdLevel2ForSubscriber(int subId, String callingPackage,
+            String callingFeatureId) {
+        return callPhoneMethodForSubIdWithPrivilegedCheck(subId,
+                "getGroupIdLevel2", (phone)-> {
+                    enforceTelephonyFeatureWithException(callingPackage,
+                            PackageManager.FEATURE_TELEPHONY_SUBSCRIPTION,
+                            "getGroupIdLevel2ForSubscriber");
+                    return phone.getGroupIdLevel2();
+                });
+    }
+
     /** Below are utility methods that abstracts the flow that many public methods use:
      *  1. Check permission: pass, throw exception, or fails (returns false).
      *  2. clearCallingIdentity.