mockftpserver: Remove pom.xml files am: 1fcee32776 am: 6944975bdd am: 59fc86a72d am: ad0dc47c99

Original change: https://android-review.googlesource.com/c/platform/external/mockftpserver/+/1817967

Change-Id: I045f7d3fe75d47a037203e5c7a802b4bad92ecf7