Not sure about target component for this bug, feel free to change.

This bug is seen on this build (probably also before):
https://jenkins.opendaylight.org/integration/view/Integration%20jobs/job/integration-helium-project-centralized-integration/110/

Steps to reproduce:
1. bin/start
2. bin/client feature:install odl-bgpcep-all odl-restconf-noauth odl-netconf-connector-all
3a.
curl -H "Accept:application/json" 127.0.0.1:8181/restconf/config/opendaylight-inventory:nodes/node/controller-config/yang-ext:mount/config:modules/module/odl-bgp-rib-impl-cfg:rib-impl/example-bgp-rib/odl-bgp-rib-impl-cfg:extensions
returns:
{"odl-bgp-rib-impl-cfg:extensions":{"name":"global-rib-extensions","type":"odl-bgp-rib-spi-cfg:consumer-extensions"}}
3b.
curl -H "Accept:application/xml" 127.0.0.1:8181/restconf/config/opendaylight-inventory:nodes/node/controller-config/yang-ext:mount/config:modules/module/odl-bgp-rib-impl-cfg:rib-impl/example-bgp-rib/odl-bgp-rib-impl-cfg:extensions
returns:
<extensions xmlns="urn:opendaylight:params:xml:ns:yang:controller:bgp:rib:impl"><name>global-rib-extensions</name><type xmlns:x="urn:opendaylight:params:xml:ns:yang:controller:bgp:rib:spi">x:consumer-extensions</type></extensions>

In both cases, "consumer-extensions" is wrong (namespace/prefix is ok).
Intead, "extensions" is right, as it is present in the default 41-bgp-example.xml file and it works when creating additional rib-impl modules.