As a Designer, I need to fix the message fragment, so that left right message design is enforced.

[Enderknight2016]

Acceptance Criteria:

• Received messages show up on the left.
• Sent messages show up on the right.
• visually verified during pre-existing expresso tests

[Austin-Scott]

https://stackoverflow.com/questions/22310772/change-gravity-programmatically-on-listview-item