Fix issue #3324032: It is possible to create an app that cannot...

...be uninstalled using device policy managers

Don't allow app switches while we are bringing up the confirmation
dialog.  This prevents the app from pushing us out of the intended
settings app flow.

Change-Id: Iea1ff64c054452d307f91f349a815c0b244e9af5

src/com/android/settings/DeviceAdminAdd.java

@@ -19,6 +19,7 @@ package com.android.settings;
 import org.xmlpull.v1.XmlPullParserException;
 
 import android.app.Activity;
+import android.app.ActivityManagerNative;
 import android.app.AlertDialog;
 import android.app.Dialog;
 import android.app.admin.DeviceAdminInfo;
@@ -35,6 +36,7 @@ import android.content.res.Resources;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.RemoteCallback;
+import android.os.RemoteException;
 import android.text.TextUtils.TruncateAt;
 import android.util.Log;
 import android.view.Display;
@@ -193,6 +195,12 @@ public class DeviceAdminAdd extends Activity {
                     }
                     finish();
                 } else {
+                    try {
+                        // Don't allow the admin to put a dialog up in front
+                        // of us while we interact with the user.
+                        ActivityManagerNative.getDefault().stopAppSwitches();
+                    } catch (RemoteException e) {
+                    }
                     mDPM.getRemoveWarning(mDeviceAdmin.getComponent(),
                             new RemoteCallback(mHandler) {
                         @Override
@@ -202,6 +210,10 @@ public class DeviceAdminAdd extends Activity {
                                             DeviceAdminReceiver.EXTRA_DISABLE_WARNING)
                                     : null;
                             if (msg == null) {
+                                try {
+                                    ActivityManagerNative.getDefault().resumeAppSwitches();
+                                } catch (RemoteException e) {
+                                }
                                 mDPM.removeActiveAdmin(mDeviceAdmin.getComponent());
                                 finish();
                             } else {