Install ironic-inspector in bifrost

Bifrost has moved to use the native in-band inspection support in
Ironic[1]. Some features are missing (such as introspection rules), so
it may still be desirable to use ironic-inspector for these use cases.
It also requires changes to the inspection interface of the ironic nodes
(ironic-inspector -> agent), so it also desirable to support
ironic-inspector for backwards compatability reasons. We should consider
dropping ironic-inspector once the native interface reaches feature
parity.

This will install ironic-inspector into the image, but will still
require configuration in bifrost.yml to use it.

[1] dcbf1d98b9

Change-Id: I3cc8455647339c67ba51620d5aff8a3acbf58dab
Partial-Bug: #2054685

docker/bifrost/bifrost-base/Dockerfile.j2

@@ -47,6 +47,7 @@ RUN echo " " && \
     /bifrost/playbooks/install.yaml \
     -e git_branch={{ openstack_branch_slashed }} \
     -e ipa_upstream_release={{ openstack_branch }} \
+    -e enable_inspector=true \
     -e @/tmp/build_arg.yml && \
 {%- if base_package_type == 'deb' %}
     apt-get clean && rm -rf /var/lib/apt/lists/*'

releasenotes/notes/reenable-ironic-inspector-in-bifrost.yml-5e01af1e96528c62.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Re-enables ironic-inspector in bifrost for backwards compatability.  See
+    `LP#2054685 <https://bugs.launchpad.net/kolla/+bug/2054685>`_ for more
+    details.