Add tini with openvswitch

Containerd v1.7+ will stop openvswitch when
restarted so we need to run openvswitch as a child
process, requiring tini.

Change-Id: I2484308d1dff326db18b181051d1c4fa24511bbe

openvswitch/Dockerfile.ubuntu

@@ -1,6 +1,11 @@
 ARG FROM=docker.io/ubuntu:jammy
 FROM ${FROM}
 
+# Add Tini
+ENV TINI_VERSION v0.19.0
+ADD https://github.com/krallin/tini/releases/download/${TINI_VERSION}/tini /tini
+RUN chmod +x /tini
+
 RUN set -ex && \
     apt-get update && \
     apt-get install -y openvswitch-switch && \

openvswitch/Dockerfile.ubuntu-dpdk

@@ -3,6 +3,11 @@ FROM ${FROM}
 
 ARG DEBIAN_FRONTEND=noninteractive
 
+# Add Tini
+ENV TINI_VERSION v0.19.0
+ADD https://github.com/krallin/tini/releases/download/${TINI_VERSION}/tini /tini
+RUN chmod +x /tini
+
 RUN set -ex && \
     apt-get update && \
     apt-get -y upgrade && \