Revert "yum-plugin-ovl is now included in Amazon Linux 1 Lambdas"

This reverts commit 38f12c4.

base/build/Dockerfile

@@ -4,7 +4,16 @@ ENV PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/opt/bin
 
 # A couple of packages are either missing critical-ish files, or didn't make it into the tar
 RUN chmod 1777 /tmp && \
+  /usr/bin/python3 -c "from configparser import SafeConfigParser; \
+yum_conf = SafeConfigParser(); \
+yum_conf.read('/etc/yum.conf'); \
+yum_conf.has_section('main') or yum_conf.add_section('main'); \
+yum_conf.set('main', 'plugins', '1'); \
+f = open('/etc/yum.conf', 'w'); \
+yum_conf.write(f); \
+f.close();" && \
   rpm --rebuilddb && \
+  yum install -y yum-plugin-ovl && \
   yum reinstall -y setup pam shadow-utils audit-libs openssl glibc-common glibc && \
   yum groupinstall -y development && \
   yum install -y clang cmake docker python27-devel python36-devel \