S3A initialization/close slower than with v1 SDK

Hive QE have observed slowdown in LLAP queries due to time to create and close s3a filesystems instances. A key aspect of that is they keep closing the fs instances (HIVE-27884), but looking at the profiles, the reason things seem to have regressed is

• two s3 clients are being created (sync and async)
• these seem to take a lot of time scanning the classpath for "global interceptors", which is at least an O(jars) operation; #of index entries in the zip files may factor too.

Proposed:

• create async client on demand when the transfer manager is invoked
• look at why passwords are being scanned for if InstanceProfileCredentialsProvider is in use...that seems slow too

SDK wishes

• SDK maybe allow us to turn off that scan for interceptors?

attaching screenshots of the profile. storediag snippet:

[001]  fs.s3a.access.key = (unset)
[002]  fs.s3a.secret.key = (unset)
[003]  fs.s3a.session.token = (unset)
[004]  fs.s3a.server-side-encryption-algorithm = (unset)
[005]  fs.s3a.server-side-encryption.key = (unset)
[006]  fs.s3a.encryption.algorithm = (unset)
[007]  fs.s3a.encryption.key = (unset)
[008]  fs.s3a.aws.credentials.provider = "com.amazonaws.auth.InstanceProfileCredentialsProvider" [core-site.xml]