HADOOP-19351. S3A: Add config option to skip test with performance mode (#7223)


The option test.fs.s3a.performance.enabled can be set to false to disable tests of
s3 stores which knowingly break posix semantics.
These tests need to be disabled when testing object stores which do enforce
a strict model of directories and files underneath the S3 API.

Contributed by Chung En Lee
5 files changed