Change Frankfurt release to build in java 8
Issue-ID: SDC-3363
Signed-off-by: sebdet <sebastien.determe@intl.att.com>
Change-Id: I83dbfe811d074cd28c5007815fa6559152bf0737
     stream:
       - 'master':
           branch: 'master'
+          java-version: openjdk11
       - 'guilin':
           branch: 'guilin'
+          java-version: openjdk11
       - 'frankfurt':
           branch: 'frankfurt'
+          java-version: openjdk8
     mvn-settings: 'sdc-settings'
-    java-version: openjdk11
     files: '**'
     archive-artifacts: ''
     build-node: ubuntu1804-docker-8c-8g