Remove stub since proper delegate is implemented

The delegate was added to ArcDevicePolicyManagerWrapperService

Bug: 160457441
Test: Threehugger
Change-Id: I219abd5f48ff345b97cf5771dc18f0188795022f

services/devicepolicy/java/com/android/server/devicepolicy/BaseIDevicePolicyManager.java

@@ -22,8 +22,6 @@ import android.util.Slog;
 
 import com.android.server.SystemService;
 
-import java.util.List;
-
 /**
  * Defines the required interface for IDevicePolicyManager implemenation.
  *
@@ -103,9 +101,4 @@ abstract class BaseIDevicePolicyManager extends IDevicePolicyManager.Stub {
     public boolean canProfileOwnerResetPasswordWhenLocked(int userId) {
         return false;
     }
-
-    public List<String> getKeyPairGrants(String callerPackage, String alias) {
-        // STOPSHIP: implement delegation code in ArcDevicePolicyManagerWrapperService & nuke this.
-        return null;
-    }
 }