Remove customizable for plugins_pip_packages

The pip packages are normally already configurable with the
<image_name>_pip_packages variable. It doesn't make much sense to make
the list of packages installed with the plugins mechanism configurable
via the <image_name>_plugins_pip_packages variable too.

And even if we wanted to, the parameter to the `customizable()`
function should be 'plugins_pip_packages' and not 'pip_packages'.

This commit removes the customizable bits from the plugins install
macro, at least until we get a good use case for it.

Change-Id: I90dd28b8c5d981e6028af353e34645712ef09b0b

docker/keystone/keystone/Dockerfile.j2

@@ -17,7 +17,7 @@ ADD plugins-archive /
 ] %}
 
 RUN if [ "$(ls /plugins)" ]; then \
-        {{ macros.install_pip(keystone_plugins_pip_packages | customizable("pip_packages")) }}; \
+        {{ macros.install_pip(keystone_plugins_pip_packages) }}; \
     fi
 
 {% endif %}

docker/neutron/neutron-metadata-agent-ovn/Dockerfile.j2

@@ -28,7 +28,7 @@ ADD plugins-archive /
     ] %}
 
 RUN if [ "$(ls /plugins)" ]; then \
-        {{ macros.install_pip(neutron_metadata_agent_ovn_plugins_pip_packages | customizable("pip_packages")) }}; \
+        {{ macros.install_pip(neutron_metadata_agent_ovn_plugins_pip_packages) }}; \
     fi
 
 {% endif %}

docker/neutron/neutron-server-opendaylight/Dockerfile.j2

@@ -39,7 +39,7 @@ ADD plugins-archive /
 ] %}
 
 RUN if [ "$(ls /plugins)" ]; then \
-        {{ macros.install_pip(neutron_server_opendaylight_plugins_pip_packages | customizable("pip_packages")) }}; \
+        {{ macros.install_pip(neutron_server_opendaylight_plugins_pip_packages) }}; \
     fi
 
 {% endif %}

docker/neutron/neutron-server-ovn/Dockerfile.j2

@@ -23,7 +23,7 @@ ADD plugins-archive /
 ] %}
 
 RUN if [ "$(ls /plugins)" ]; then \
-        {{ macros.install_pip(neutron_server_ovn_plugins_pip_packages | customizable("pip_packages")) }}; \
+        {{ macros.install_pip(neutron_server_ovn_plugins_pip_packages) }}; \
     fi
 
 {% endif %}

docker/neutron/neutron-server/Dockerfile.j2

@@ -39,7 +39,7 @@ LABEL maintainer="{{ maintainer }}" name="{{ image_name }}" build-date="{{ build
 ADD plugins-archive /
 RUN {{ macros.install_pip(neutron_server_pip_packages | customizable("pip_packages")) }} \
     && if [ "$(ls /plugins)" ]; then \
-           {{ macros.install_pip(neutron_server_plugins_pip_packages | customizable("pip_packages")) }}; \
+           {{ macros.install_pip(neutron_server_plugins_pip_packages) }}; \
        fi
 
 {% endif %}

docker/nova/nova-compute/Dockerfile.j2

@@ -141,7 +141,7 @@ RUN mkdir -p /etc/ceph
 ADD plugins-archive /
 RUN {{ macros.install_pip(nova_compute_pip_packages | customizable("pip_packages")) }} \
     && if [ "$(ls /plugins)" ]; then \
-           {{ macros.install_pip(nova_compute_plugins_pip_packages | customizable("pip_packages")) }}; \
+           {{ macros.install_pip(nova_compute_plugins_pip_packages) }}; \
        fi
 
 {% endif %}