Update outdated packages on centos and oracle hosts

tests/foreman/api/test_convert2rhel.py

@@ -155,6 +155,7 @@ def centos(
     """Deploy and register Centos host"""
     # updating centos packages on CentOS 8 is necessary for conversion
     major = version.split('.')[0]
+    centos_host.execute('yum -y update')
     if major == '8':
         centos_host.execute('yum -y update centos-*')
     repo_url = settings.repos.convert2rhel.convert_to_rhel_repo.format(major)
@@ -199,6 +200,7 @@ def oracle(
     # disable rhn-client-tools because it obsoletes the subscription manager package
     oracle_host.execute('echo "exclude=rhn-client-tools" >> /etc/yum.conf')
     # install and set correct kernel, based on convert2rhel docs
+    oracle_host.execute('yum -y update kernel*')
     result = oracle_host.execute(
         'yum install -y kernel && '
         'grubby --set-default /boot/vmlinuz-'
@@ -263,6 +265,7 @@ def test_convert2rhel_oracle(module_target_sat, oracle, activation_key_rhel, ver
 
     :CaseImportance: Medium
     """
+    oracle.execute('yum -y update')
     host_content = module_target_sat.api.Host(id=oracle.hostname).read_json()
     assert host_content['operatingsystem_name'] == f"OracleLinux {version}"