Fix aux reverb issues:

Fix aux reverb issues:

- when creating an effect, only pass the effect type to the
 AudioEffect framework so it selects whether to use an insert
 or aux effect based on the session.
- SL ES aux reverb effects don't have an explicit SetEnabled()
 function, so enable the effect upon creation, or based on the
preset for the preset reverb effect.

Add a test for SLEffectSend.

Change-Id: I683331cac19cf1fb9628d636569ab3d342c02820