[SPARK-10957][ML] setParams changes quantileProbabilities unexpectly in PySpark's AFTSurvivalRegression

[mengxr]

If user doesn't specify quantileProbs in setParams, it will get reset to the default value. We don't need special handling here. @vectorijk @yanboliang

[SparkQA]

Test build #43297 has finished for PR 9001 at commit 4053630.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):
  • class AFTSurvivalRegression(JavaEstimator, HasFeaturesCol, HasLabelCol, HasPredictionCol,
  • class AFTSurvivalRegressionModel(JavaModel):

[vectorijk]

It would make sense.

[mengxr]

Merged into master.