## What changes were proposed in this pull request?
Before the patch, Spark could infer as Date a partition value which cannot be casted to Date (this can happen when there are extra characters after a valid date, like `2018-02-15AAA`).
When this happens and the input format has metadata which define the schema of the table, then `null` is returned as a value for the partition column, because the `cast` operator used in (`PartitioningAwareFileIndex.inferPartitioning`) is unable to convert the value.
The PR checks in the partition inference that values can be casted to Date and Timestamp, in order to infer that datatype to them.
## How was this patch tested?
added UT
Author: Marco Gaido <marcogaido91@gmail.com>
Closes#20621 from mgaido91/SPARK-23436.
651b0277fe