Fix AccountManagerServiceTest

Unregister AccountManagerInternal before creating a new instance of
AccountManagerService, otherwise it will cause:
java.lang.IllegalStateException: Overriding service registration

Also overrode MockPm.addOnPermissionsChangeListener to be a noop and
not throw an exception.

Bug: 31071079
Change-Id: I0d24232eba655a68bf3fb38d7aa9edb92d469cea

services/tests/servicestests/src/com/android/server/accounts/AccountManagerServiceTest.java

diff --git a/services/tests/servicestests/src/com/android/server/accounts/AccountManagerServiceTest.java b/services/tests/servicestests/src/com/android/server/accounts/AccountManagerServiceTest.java
index 404c142..a3d0afa 100644
--- a/services/tests/servicestests/src/com/android/server/accounts/AccountManagerServiceTest.java
+++ b/services/tests/servicestests/src/com/android/server/accounts/AccountManagerServiceTest.java
@@ -21,6 +21,7 @@
 import static org.mockito.Mockito.when;
 
 import android.accounts.Account;
+import android.accounts.AccountManagerInternal;
 import android.accounts.AuthenticatorDescription;
 import android.app.AppOpsManager;
 import android.app.Notification;
@@ -44,6 +45,8 @@
 import android.test.mock.MockPackageManager;
 import android.util.Log;
 
+import com.android.server.LocalServices;
+
 import java.io.File;
 import java.io.FileDescriptor;
 import java.io.PrintWriter;
@@ -73,6 +76,7 @@
         SQLiteDatabase.deleteDatabase(new File(mAms.getCeDatabaseName(UserHandle.USER_SYSTEM)));
         SQLiteDatabase.deleteDatabase(new File(mAms.getDeDatabaseName(UserHandle.USER_SYSTEM)));
         SQLiteDatabase.deleteDatabase(new File(mAms.getPreNDatabaseName(UserHandle.USER_SYSTEM)));
+        LocalServices.removeServiceForTest(AccountManagerInternal.class);
         super.tearDown();
     }
 
@@ -282,6 +286,7 @@
 
     private AccountManagerService createAccountManagerService(Context mockContext,
             Context realContext) {
+        LocalServices.removeServiceForTest(AccountManagerInternal.class);
         return new MyAccountManagerService(mockContext,
                 new MyMockPackageManager(), new MockAccountAuthenticatorCache(), realContext);
     }
@@ -420,6 +425,11 @@
         public int checkSignatures(final int uid1, final int uid2) {
             return PackageManager.SIGNATURE_MATCH;
         }
+
+        @Override
+        public void addOnPermissionsChangeListener(
+                OnPermissionsChangedListener listener) {
+        }
     }
 
     static public class MyAccountManagerService extends AccountManagerService {