Fix UBI image: Add -y option to install of hostname

Summary:
dnf install hostname was failing waiting for user interaction.  Add the -y option
to avoid that.

Test Plan: Built the UBI:8 image locally

Reviewers: devops, dshubin, steve.varnau

Reviewed By: dshubin, steve.varnau

Subscribers: devops

Differential Revision: https://phorge.dev.yugabyte.com/D38602

docker/images/yugabyte/Dockerfile

@@ -41,8 +41,8 @@ ENV YB_DEVOPS_USE_PYTHON3=1
 WORKDIR $YB_HOME
 
 # Create some yum aliases for use in this Dockerfile
-ARG yum_install="yum install --disableplugin=subscription-manager"
-ARG yum_upgrade="yum upgrade --disableplugin=subscription-manager"
+ARG yum_install="yum install --disableplugin=subscription-manager -y"
+ARG yum_upgrade="yum upgrade --disableplugin=subscription-manager -y"
 
 # Add the almalinux8 package repo if we are building for ubi.
 RUN <<EOF
@@ -67,20 +67,20 @@ EOF
 
 # Install hostname for ubi8 images.
 RUN if [[ "$BASE_IMAGE" == "registry.access.redhat.com/ubi8/ubi"* ]]; then \
-  dnf install hostname; \
+  $yum_install hostname; \
   fi
 
 # Ensure our base system is fully up to date
 RUN set -x; \
-  $yum_upgrade -y \
+  $yum_upgrade \
   && rm -rf ~/.cache \
   && yum clean all && rm -rf /var/cache/yum
 
 # Install required python packages first
 # this should leave us with python3.8 as the default python3
 # We need to explicitly remove the old pip wheel file to avoid tripping vulnerability scans
 RUN set -x ; \
-   $yum_install -y  \
+   $yum_install  \
       python38-devel \
       python38-pip \
       python38-psutil \