Dialer: Set mPhoneStateListener listen sub1 and sub2's phone state change

mPhoneStateListener only listen sub1's phone state change,
so when make call from sub2, and enter dialer again, sub1's
phone state will be idle, then won't show dialpad chooser.

Set mPhoneStateListener listen sub1 and sub2's phone state
change, and only when call state is idle, and dialpad chooser
is visible, set dialpad chooser invisible.

CRs-Fixed: 752420

Change-Id: I8b966702f9efc302d7ae83e3e036b2cb8104697a