[SPARK-15520][SQL] Also set sparkContext confs when using SparkSession builder in pyspark
[SPARK-15520][SQL] Also set sparkContext confs when using SparkSession builder in pyspark

## What changes were proposed in this pull request?

Also sets confs in the underlying sc when using SparkSession.builder.getOrCreate(). This is a bug-fix from a post-merge comment in https://github.com/apache/spark/pull/13289

## How was this patch tested?

Python doc-tests.

Author: Eric Liang <ekl@databricks.com>

Closes #13309 from ericl/spark-15520-1.

(cherry picked from commit 594a1bf200fea8d6bcf25839a49186f66f922bc8)
Signed-off-by: Andrew Or <02e0a999c50b1f88df7a8f5a04e1b76b35ea6a88@databricks.com>

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