Previously horizon configuration and start are done too early
and as a result horizon init and start need to be run twice
after horizon plugins are enabled.
- horizon config was done before "run_phase stack install"
- horizon init and start were done before "run_phase stack post-config"
This commit rearrange horizon setup to the appropriate phases
defined in the devstack plugin interface.
- Configuration of horizon settings is moved to configure_horizon.
- horizon config is now called between run_phase stack install
and post-config.
- horizon init and start are now called between run_phase stack
post-config and extra.
Change-Id: I8bf2ceaf7734c4f7cec68bc05d7cdbae81ef311e
43f62c0849