Initialize parent instance of DevicePolicyManager earlier

Otherwise in the onCreatePreferences() method of the subclass, it
will get the incorrect DevicePolicyManager instance.

Bug: 30030055
Change-Id: Ie54dbc38b3767dedf94f1ce393a191c9a567fe62
(cherry picked from commit 4a91d63181220e6de606c8480bc3ed20d4043e0c)

Author: Rubin Xu

app/src/main/java/com/afwsamples/testdpc/common/ProfileOrParentFragment.java

@@ -169,6 +169,10 @@ public void onCreate(Bundle savedInstanceState) {
         mProfileOwner = mDevicePolicyManager.isProfileOwnerApp(getActivity().getPackageName());
         mDeviceOwner = mDevicePolicyManager.isDeviceOwnerApp(getActivity().getPackageName());
 
+        if (mParentInstance) {
+            mDevicePolicyManager = mDevicePolicyManager.getParentProfileInstance(mAdminComponent);
+        }
+
         // Put at last to make sure all initializations above are done before subclass's
         // onCreatePreferences is called.
         super.onCreate(savedInstanceState);
@@ -177,7 +181,6 @@ public void onCreate(Bundle savedInstanceState) {
         // This needs to be called after super.onCreate because preference manager is set up
         // inside super.onCreate.
         if (mParentInstance) {
-            mDevicePolicyManager = mDevicePolicyManager.getParentProfileInstance(mAdminComponent);
             final PreferenceManager pm = getPreferenceManager();
             pm.setSharedPreferencesName(pm.getSharedPreferencesName() + TAG_PARENT);
         }