[SPARK-15954][SQL] Disable loading test tables in Python tests

## What changes were proposed in this pull request?
This patch introduces a flag to disable loading test tables in TestHiveSparkSession and disables that in Python. This fixes an issue in which python/run-tests would fail due to failure to load test tables.

Note that these test tables are not used outside of HiveCompatibilitySuite. In the long run we should probably decouple the loading of test tables from the test Hive setup.

## How was this patch tested?
This is a test only change.

Author: Reynold Xin <[email protected]>

Closes #14005 from rxin/SPARK-15954.

(cherry picked from commit 38f4d6f)
Signed-off-by: Reynold Xin <[email protected]>

Author: rxin

python/pyspark/sql/context.py

@@ -492,7 +492,7 @@ def _createForTesting(cls, sparkContext):
         confusing error messages.
         """
         jsc = sparkContext._jsc.sc()
-        jtestHive = sparkContext._jvm.org.apache.spark.sql.hive.test.TestHiveContext(jsc)
+        jtestHive = sparkContext._jvm.org.apache.spark.sql.hive.test.TestHiveContext(jsc, False)
         return cls(sparkContext, jtestHive)
 
     def refreshTable(self, tableName):