Register OnAttachStateChangeListener before attaching to container.

If we do the reverse, there is a change onAttach will occur before the
callback is registered and invokable (e.g. overlay window already exists
for EDU).

Test: Manual
Fix: 299335210
Flag: None
Change-Id: Ic4befe900c9582e1b01c2bc4699b431f95efa617
1 file changed