### What changes were proposed in this pull request?
Now that we merged the Koalas main code into the PySpark code base (#32036), we should port the Koalas DataFrame unit test to PySpark.
### Why are the changes needed?
Currently, the pandas-on-Spark modules are not tested at all. We should enable the DataFrame unit test first.
### Does this PR introduce _any_ user-facing change?
No.
### How was this patch tested?
Enable the DataFrame unit test.
Closes#32083 from xinrong-databricks/port.test_dataframe.
Authored-by: Xinrong Meng <xinrong.meng@databricks.com>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
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