Fix bug 5339708 - edge case in ListView focus restoration

Some apps have managed to hit this edge case in monkey runs. In
layoutChildren an attempt to findFocus() fails when items are
focusable. When ListView attempts to restore focus to this view,
bad things happen.

Change-Id: Ie8bb1bab847898e342c16fbe3ff1a6153d6f69df

Author: adamp

core/java/android/widget/ListView.java

@@ -1651,6 +1651,7 @@ protected void layoutChildren() {
                 // are focusable
                 if (mItemsCanFocus && hasFocus() && !sel.hasFocus()) {
                     final boolean focusWasTaken = (sel == focusLayoutRestoreDirectChild &&
+                            focusLayoutRestoreView != null &&
                             focusLayoutRestoreView.requestFocus()) || sel.requestFocus();
                     if (!focusWasTaken) {
                         // selected item didn't take focus, fine, but still want