Port stx-nova-api-proxy image to stx-debian

This change enables building the stx-nova-api-proxy image within the
Debian build framework. It is now based on stx-debian and following the
new convention for StarlingX images.

Test Plan:
PASS: Build stx-nova-api-proxy image
PASS: Manually upload built image to a system, use helm-override to
      change the nova-api-proxy container image and apply stx-openstack
PASS: Ensure the nova-api-proxy pod successfully starts and is running
PASS: Ensure nova-api-proxy pod liveness and readiness probes are
      healthy

Depends-On: https://review.opendev.org/c/starlingx/root/+/871314

Story: 2010072
Task: 47217

Signed-off-by: Luan Nunes Utimura <LuanNunes.Utimura@windriver.com>
Change-Id: I80e4a046e6ae89b1dae2f583fb14723713194e45

debian_stable_docker_images.inc

@@ -0,0 +1 @@
+./nova-api-proxy

debian_stable_wheels.inc

@@ -0,0 +1 @@
+nova-api-proxy-wheels

nova-api-proxy/debian/stx-nova-api-proxy.stable_docker_image

@@ -0,0 +1,7 @@
+BUILDER=loci
+LABEL=stx-nova-api-proxy
+PROJECT=infra
+PROJECT_REPO=nil
+PIP_PACKAGES="api_proxy eventlet oslo.config oslo.log \
+              paste PasteDeploy routes webob keystonemiddleware"
+DIST_REPOS="OS"