Set JAVA_HOME in example-setup Dockerfile

Change-Id: Ib952c1f225a1e7c44399689ec98999c4e4f7ac77

example-setup/broker/Dockerfile

diff --git a/example-setup/broker/Dockerfile b/example-setup/broker/Dockerfile
index e9abc46..980b73a 100644
--- a/example-setup/broker/Dockerfile
+++ b/example-setup/broker/Dockerfile
@@ -18,4 +18,6 @@
 COPY --chown=gerrit:gerrit configs/replication.config.template /var/gerrit/etc/
 COPY --chown=gerrit:gerrit configs/gerrit.config.template /var/gerrit/etc/
 
+ENV JAVA_HOME=/usr/lib/jvm/jre-21
+
 ENTRYPOINT [ "/tmp/entrypoint.sh" ]

example-setup/http/Dockerfile

diff --git a/example-setup/http/Dockerfile b/example-setup/http/Dockerfile
index cb4d765..526f37a 100644
--- a/example-setup/http/Dockerfile
+++ b/example-setup/http/Dockerfile
@@ -11,4 +11,6 @@
 COPY --chown=gerrit:gerrit configs/replication.config.template /var/gerrit/etc/
 COPY --chown=gerrit:gerrit configs/gerrit.config.template /var/gerrit/etc/
 
+ENV JAVA_HOME=/usr/lib/jvm/jre-21
+
 ENTRYPOINT [ "/tmp/entrypoint.sh" ]