AclManagerTest/RepPolicyEntryHandlerTest should use realistic service user path

the code lines to add service users in AclManagerTest like
https://github.com/apache/sling-org-apache-sling-feature-cpconverter/blob/master/src/test/java/org/apache/sling/feature/cpconverter/acl/AclManagerTest.java#L74

or
https://github.com/apache/sling-org-apache-sling-feature-cpconverter/blob/master/src/test/java/org/apache/sling/feature/cpconverter/acl/AclManagerTest.java#L79

are a bit confusing to read. the path "/asd/public" would neither with a default jackrabbit/oak repository nor with Adobe AEM represent a valid path for a service user.... this makes it hard to understand the intention behind the code (see also SLING-9959 for why this matters).

i would suggest to either use an absolute path starting with "/home/users/system" or the corresponding default path in Jackrabbit Oak concatenated with some arbitrary node name for the user node itself.