Avoid showing DeviceAdminAdd screen in the background of support dialog.

Change-Id: Idb2f98012fc161decef579c1e87cca0f8ade2619
Fixes: 27665715
diff --git a/src/com/android/settings/DeviceAdminAdd.java b/src/com/android/settings/DeviceAdminAdd.java
index 364700b..d2ba508 100644
--- a/src/com/android/settings/DeviceAdminAdd.java
+++ b/src/com/android/settings/DeviceAdminAdd.java
@@ -82,6 +82,9 @@
     public static final String EXTRA_DEVICE_ADMIN_PACKAGE_NAME =
             "android.app.extra.DEVICE_ADMIN_PACKAGE_NAME";
 
+    public static final String EXTRA_CALLED_FROM_SUPPORT_DIALOG =
+            "android.app.extra.CALLED_FROM_SUPPORT_DIALOG";
+
     Handler mHandler;
 
     DevicePolicyManager mDPM;
@@ -113,6 +116,8 @@
     int mCurSysAppOpMode;
     int mCurToastAppOpMode;
 
+    boolean mIsCalledFromSupportDialog = false;
+
     @Override
     protected void onCreate(Bundle icicle) {
         super.onCreate(icicle);
@@ -129,6 +134,8 @@
             return;
         }
 
+        mIsCalledFromSupportDialog = getIntent().getBooleanExtra(
+                EXTRA_CALLED_FROM_SUPPORT_DIALOG, false);
 
         String action = getIntent().getAction();
         ComponentName who = (ComponentName)getIntent().getParcelableExtra(
@@ -459,6 +466,18 @@
     }
 
     @Override
+    protected void onUserLeaveHint() {
+        super.onUserLeaveHint();
+        // In case this is triggered from support dialog, finish this activity once the user leaves
+        // so that this won't appear as a background next time support dialog is triggered. This
+        // is because the support dialog activity and this belong to the same task and we can't
+        // start this in new activity since we need to know the calling package in this activity.
+        if (mIsCalledFromSupportDialog) {
+            finish();
+        }
+    }
+
+    @Override
     protected Dialog onCreateDialog(int id, Bundle args) {
         switch (id) {
             case DIALOG_WARNING: {
diff --git a/src/com/android/settings/ShowAdminSupportDetailsDialog.java b/src/com/android/settings/ShowAdminSupportDetailsDialog.java
index 2f2379a..fce669c 100644
--- a/src/com/android/settings/ShowAdminSupportDetailsDialog.java
+++ b/src/com/android/settings/ShowAdminSupportDetailsDialog.java
@@ -155,6 +155,7 @@
                             intent.setClass(activity, DeviceAdminAdd.class);
                             intent.putExtra(DevicePolicyManager.EXTRA_DEVICE_ADMIN,
                                     enforcedAdmin.component);
+                            intent.putExtra(DeviceAdminAdd.EXTRA_CALLED_FROM_SUPPORT_DIALOG, true);
                             // DeviceAdminAdd class may need to run as managed profile.
                             activity.startActivityAsUser(intent,
                                     new UserHandle(enforcedAdmin.userId));