Wait for Couchbase to be ready before node-init

Changes:
* Make install_if_needed consistent with MongoDB
* Don't run node-init as part of install_if_needed
* Start Couchbase and poll until ready before node-init

Closes-Bug: #1325753
Change-Id: I1bbb616b6ec2eb6b83faa30f597a6331421542fb
Merge "Wait for Couchbase to be ready before node-init"