SearchView: Add some more listeners, IME dismiss improvements and focus control.

Addresses following bugs:
3067611 : Submit button incorrectly displayed
3064371 : Callback to report suggestion click
3008580 : Setting initial focus

The SearchView will take initial focus now, reverting an earlier change. If
you don't want it to take initial focus, then you must requestFocus on a
different view on launching the activity, since the initial focus is desirable
in other cases. This is normal behavior for all EditText widgets and SearchView
shouldn't have a different behavior.