On uninstall cred mng app

Changes
* when ACTION_PACKAGE_REMOVE is received
  in the DPMS broadcast receiver, remove
  the cred mng app if the removed package
  is the cred mng app.

Manual testing steps:
* Request to manage credentials in TestDPC
* Check Settings > encryption & credentials
  and verify the cred mng app is set successfully
* Uninstall TestDPC
* Check Settings to and verify there is no
  cred mng app.

Bug: 165641221
Test: Manual testing
      atest com.android.server.devicepolicy.DevicePolicyManagerTest
Change-Id: I6e8004da40c35c0dfe25540bf143f255d9f839d7

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

@@ -819,6 +819,7 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {
             } else if (Intent.ACTION_PACKAGE_REMOVED.equals(action)
                     && !intent.getBooleanExtra(Intent.EXTRA_REPLACING, false)) {
                 handlePackagesChanged(intent.getData().getSchemeSpecificPart(), userHandle);
+                removeCredentialManagementApp(intent.getData().getSchemeSpecificPart());
             } else if (Intent.ACTION_MANAGED_PROFILE_ADDED.equals(action)) {
                 clearWipeProfileNotification();
             } else if (Intent.ACTION_DATE_CHANGED.equals(action)
@@ -949,6 +950,20 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {
         }
     }
 
+    private void removeCredentialManagementApp(String packageName) {
+        mBackgroundHandler.post(() -> {
+            try (KeyChainConnection connection = mInjector.keyChainBind()) {
+                IKeyChainService service = connection.getService();
+                if (service.hasCredentialManagementApp()
+                        && packageName.equals(service.getCredentialManagementAppPackageName())) {
+                    service.removeCredentialManagementApp();
+                }
+            } catch (RemoteException | InterruptedException | IllegalStateException e) {
+                Log.e(LOG_TAG, "Unable to remove the credential management app");
+            }
+        });
+    }
+
     private boolean isRemovedPackage(String changedPackage, String targetPackage, int userHandle) {
         try {
             return targetPackage != null
@@ -1419,6 +1434,10 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {
             return SecurityLog.isLoggingEnabled();
         }
 
+        KeyChainConnection keyChainBind() throws InterruptedException {
+            return KeyChain.bind(mContext);
+        }
+
         KeyChainConnection keyChainBindAsUser(UserHandle user) throws InterruptedException {
             return KeyChain.bindAsUser(mContext, user);
         }

services/tests/servicestests/src/com/android/server/devicepolicy/DevicePolicyManagerServiceTestable.java

@@ -459,6 +459,11 @@ public class DevicePolicyManagerServiceTestable extends DevicePolicyManagerServi
             return services.buildMock.isDebuggable;
         }
 
+        @Override
+        KeyChain.KeyChainConnection keyChainBind() {
+            return services.keyChainConnection;
+        }
+
         @Override
         KeyChain.KeyChainConnection keyChainBindAsUser(UserHandle user) {
             return services.keyChainConnection;

services/tests/servicestests/src/com/android/server/devicepolicy/DevicePolicyManagerTest.java

@@ -1616,6 +1616,33 @@ public class DevicePolicyManagerTest extends DpmTestBase {
                 )), eq(user));
     }
 
+    @Test
+    public void testRemoveCredentialManagementApp() throws Exception {
+        final String packageName = "com.test.cred.mng";
+        Intent intent = new Intent(Intent.ACTION_PACKAGE_REMOVED);
+        intent.setData(Uri.parse("package:" + packageName));
+        dpms.mReceiver.setPendingResult(
+                new BroadcastReceiver.PendingResult(Activity.RESULT_OK,
+                        "resultData",
+                        /* resultExtras= */ null,
+                        BroadcastReceiver.PendingResult.TYPE_UNREGISTERED,
+                        /* ordered= */ true,
+                        /* sticky= */ false,
+                        /* token= */ null,
+                        CALLER_USER_HANDLE,
+                        /* flags= */ 0));
+        when(getServices().keyChainConnection.getService().hasCredentialManagementApp())
+                .thenReturn(true);
+        when(getServices().keyChainConnection.getService().getCredentialManagementAppPackageName())
+                .thenReturn(packageName);
+
+        dpms.mReceiver.onReceive(mContext, intent);
+
+        flushTasks(dpms);
+        verify(getServices().keyChainConnection.getService()).hasCredentialManagementApp();
+        verify(getServices().keyChainConnection.getService()).removeCredentialManagementApp();
+    }
+
     /**
      * Simple test for delegate set/get and general delegation. Tests verifying that delegated
      * privileges can acually be exercised by a delegate are not covered here.