Implement actionbar menu items for DeploymentActivity, fixes T764

Summary:
  - Add two actionbar menu items that supports both icons and labels
  - Implement `onOptionsItemSelected` at `DeploymentActivity` so when the plus icon is tapped, it launches the `Add Deployment` activity

Test Plan:
  - Build and install app.
  - Launch app.
  - See list deployments activity show up.
  - See two actionbar menu items, plus and list icons.
  - Tap on the plus icon to launch the `Add Deployment` activity.

Reviewers: dkobia

Subscribers: rjmackay

Maniphest Tasks: T764

Differential Revision: https://phabricator.ushahidi.com/D345