[SPARK-3516] [mllib] DecisionTree: Add minInstancesPerNode, minInfoGain params to example and Python API

[jkbradley]

Added minInstancesPerNode, minInfoGain params to:

• DecisionTreeRunner.scala example
• Python API (tree.py)

Also:

• Fixed typo in tree suite test "do not choose split that does not satisfy min instance per node requirements"
• small style fixes

CC: @mengxr

[SparkQA]

QA tests have started for PR 2349 at commit 95c479d.

• This patch merges cleanly.

[SparkQA]

QA tests have started for PR 2349 at commit 95c479d.

• This patch merges cleanly.

[SparkQA]

QA tests have finished for PR 2349 at commit 95c479d.

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

[SparkQA]

QA tests have finished for PR 2349 at commit 95c479d.

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

[davies]

Why "don't" is typo?

[jkbradley]

Not really a typo. But I figured that, if people are munging logs from tests, quote characters might be troublesome to deal with.

[davies]

It sounds reasonable, thanks.

[davies]

This patch looks good to me, just one minor question.

[jkbradley]

@davies Thanks for taking a look!

[mengxr]

@jkbradley This contains API changes to python. Could you create a JIRA for it? Thanks!

[SparkQA]

QA tests have started for PR 2349 at commit a95e7c8.

• This patch merges cleanly.

[SparkQA]

QA tests have started for PR 2349 at commit 61b2e72.

• This patch merges cleanly.

[SparkQA]

QA tests have finished for PR 2349 at commit a95e7c8.

• This patch fails unit tests.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):
  • throw new IllegalStateException("The main method in the given main class must be static")

[jkbradley]

Unrelated failure (in streaming)

[SparkQA]

QA tests have finished for PR 2349 at commit 61b2e72.

• This patch passes unit tests.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):
  • throw new IllegalStateException("The main method in the given main class must be static")

[jkbradley]

@mengxr This patch should be ready to check now. Thanks!

[mengxr]

LGTM. Merged into master. Thanks!