Conference event package performance improvement.

- Instead of sending each participant to the telephony conference
controller, all participants are sent at once.  This way the conference
only needs to be recalculated once.
- New connections are created with state NEW so that they are not shown
in the InCall UI.
- Once the conference is established, the state of the connections is
set appropriately based on the information in the conference event
package.

Bug: 18057361
Change-Id: Ibdb5cb940f15ab6d872bf1ef8c99a1a9ebae7b6e
4 files changed