[SPARK-3627] - [yarn] - fix exit code and final status reporting to RM

See the description and whats handled in the jira comment: https://issues.apache.org/jira/browse/SPARK-3627?focusedCommentId=14150013&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14150013

This does not handle yarn client mode reporting of the driver to the AM.   I think that should be handled when we make it an unmanaged AM.

this pr didn't change this code, other then wrapping it with an if.  Its also going to be deprecated soon so I don't see a reason to fix  it.