Download the mysql RPM file before install (#1787)

docker/kanister-mysql/image/Dockerfile

@@ -3,7 +3,10 @@ FROM registry.access.redhat.com/ubi8/ubi:8.1 as builder
 
 RUN dnf clean all && rm -rf /var/cache/dnf
 RUN dnf -y upgrade
-RUN dnf install -y https://dev.mysql.com/get/mysql80-community-release-el8-1.noarch.rpm
+# Download the RPM file to avoid timeouts during install
+RUN curl -LO https://dev.mysql.com/get/mysql80-community-release-el8-1.noarch.rpm
+# Install from the local file
+RUN dnf install -y mysql80-community-release-el8-1.noarch.rpm
 
 # GPG keys for MySQL have expired. Importing the new key below.
 # Please refer bug https://bugs.mysql.com/bug.php?id=106188 for more details