Make getDefaultCarrierServicePackageName for Mainline

Make this API system to resolve mainline concern. It is ok to make it
system API as it is not a key in CarrierConfigManager. We can add
permission check on the other side.

Test: built
Bug: 146583148
Change-Id: I7c4297d659635622ba4523abf2ce32e21f961ad0

2 files changed, 20 insertions, 4 deletions

diff --git a/api/system-current.txt b/api/system-current.txt
index 01cab53b1a94..6dad5c304958 100755
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -7912,6 +7912,7 @@ package android.telephony {
   }
 
   public class CarrierConfigManager {
+    method @NonNull @RequiresPermission(android.Manifest.permission.READ_PRIVILEGED_PHONE_STATE) public String getDefaultCarrierServicePackageName();
     method @NonNull public static android.os.PersistableBundle getDefaultConfig();
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public void overrideConfig(int, @Nullable android.os.PersistableBundle);
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public void updateConfigForPhoneId(int, String);
diff --git a/telephony/java/android/telephony/CarrierConfigManager.java b/telephony/java/android/telephony/CarrierConfigManager.java
index f222c50471e9..9dca3901924c 100644
--- a/telephony/java/android/telephony/CarrierConfigManager.java
+++ b/telephony/java/android/telephony/CarrierConfigManager.java
@@ -4023,13 +4023,28 @@ public class CarrierConfigManager {
         }
     }
 
-    /** {@hide} */
+    /**
+     * Gets the package name for a default carrier service.
+     * @return the package name for a default carrier service; empty string if not available.
+     *
+     * @hide
+     */
+    @NonNull
+    @SystemApi
+    @RequiresPermission(android.Manifest.permission.READ_PRIVILEGED_PHONE_STATE)
     public String getDefaultCarrierServicePackageName() {
         try {
-            return getICarrierConfigLoader().getDefaultCarrierServicePackageName();
-        } catch (Throwable t) {
-            return null;
+            ICarrierConfigLoader loader = getICarrierConfigLoader();
+            if (loader == null) {
+                Rlog.w(TAG, "getDefaultCarrierServicePackageName ICarrierConfigLoader is null");
+                return "";
+            }
+            return loader.getDefaultCarrierServicePackageName();
+        } catch (RemoteException ex) {
+            Rlog.e(TAG, "getDefaultCarrierServicePackageName ICarrierConfigLoader is null"
+                    + ex.toString());
         }
+        return "";
     }
 
     /**