[SPARK-32160][CORE][PYSPARK][FOLLOWUP] Change the config name to switch allow/disallow SparkContext in executors.

[ueshin]

What changes were proposed in this pull request?

This is a follow-up of #29278.
This PR changes the config name to switch allow/disallow SparkContext in executors as per the comment #29278 (review).

Why are the changes needed?

The config name spark.executor.allowSparkContext is more reasonable.

Does this PR introduce any user-facing change?

Yes, the config name is changed.

How was this patch tested?

Updated tests.

[dongjoon-hyun]

Thanks, @ueshin !

[SparkQA]

Test build #127005 has finished for PR 29340 at commit 2602fe8.

• This patch fails Spark unit tests.
• This patch merges cleanly.
• This patch adds no public classes.

[HyukjinKwon]

+1 I think this makes more sense.

[SparkQA]

Test build #127013 has finished for PR 29340 at commit 7e0f7fc.

• This patch fails Spark unit tests.
• This patch merges cleanly.
• This patch adds no public classes.

[cloud-fan]

retest this please

[HyukjinKwon]

I am merging this to get this in Spark 3.0.1. The test failure in Kafka will be fixed at #29343.

[HyukjinKwon]

Merged to master.

[dongjoon-hyun]

Please note that there is a PR for the 170 Cache related failures.

• [SPARK-32524][SQL][TESTS] SharedSparkSession should clean up InMemoryRelation.ser #29344

[SparkQA]

Test build #127023 has finished for PR 29340 at commit 7e0f7fc.

• This patch fails Spark unit tests.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #127021 has finished for PR 29340 at commit 7e0f7fc.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.