[SPARK-19970][SQL][BRANCH-2.1] Table owner should be USER instead of PRINCIPAL...

[SPARK-19970][SQL][BRANCH-2.1] Table owner should be USER instead of PRINCIPAL in kerberized clusters

## What changes were proposed in this pull request?

In the kerberized hadoop cluster, when Spark creates tables, the owner of tables are filled with PRINCIPAL strings instead of USER names. This is inconsistent with Hive and causes problems when using [ROLE](https://cwiki.apache.org/confluence/display/Hive/SQL+Standard+Based+Hive+Authorization) in Hive. We had better to fix this.

**BEFORE**
```scala
scala> sql("create table t(a int)").show
scala> sql("desc formatted t").show(false)
...
|Owner:                      |sparkEXAMPLE.COM                                         |       |
```

**AFTER**
```scala
scala> sql("create table t(a int)").show
scala> sql("desc formatted t").show(false)
...
|Owner:                      |spark                                         |       |
```

## How was this patch tested?

Manually do `create table` and `desc formatted` because this happens in Kerberized clusters.

Author: Dongjoon Hyun <dongjoon@apache.org>

Closes #17363 from dongjoon-hyun/SPARK-19970-2.