Fix dream settings initial state.

The empty view wasn't being updated initially by the fragment
so it was being left in an empty state since no preferences are
added after the fact.

Bug: 25609200
Change-Id: Ib9aa02ba94bf7077d01892d96d79d39203047f4d
diff --git a/src/com/android/settings/SettingsPreferenceFragment.java b/src/com/android/settings/SettingsPreferenceFragment.java
index d2ce285..41fd795 100644
--- a/src/com/android/settings/SettingsPreferenceFragment.java
+++ b/src/com/android/settings/SettingsPreferenceFragment.java
@@ -197,6 +197,7 @@
             mCurrentRootAdapter = getListView().getAdapter();
             mCurrentRootAdapter.registerAdapterDataObserver(mDataSetObserver);
             mIsDataSetObserverRegistered = true;
+            onDataSetChanged();
         }
     }