### What changes were proposed in this pull request?
This pr add default parallelism configuration(`spark.sql.default.parallelism`) for Spark SQL and make it effective for `LocalTableScan`.
### Why are the changes needed?
Avoid generating small files for INSERT INTO TABLE from VALUES, for example:
```sql
CREATE TABLE t1(id int) USING parquet;
INSERT INTO TABLE t1 VALUES (1), (2), (3), (4), (5), (6), (7), (8);
```
Before this pr:
```
-rw-r--r-- 1 root root 421 Dec 1 01:54 part-00000-4d5a3a89-2995-4328-b2ae-908febbbaf4a-c000.snappy.parquet
-rw-r--r-- 1 root root 421 Dec 1 01:54 part-00001-4d5a3a89-2995-4328-b2ae-908febbbaf4a-c000.snappy.parquet
-rw-r--r-- 1 root root 421 Dec 1 01:54 part-00002-4d5a3a89-2995-4328-b2ae-908febbbaf4a-c000.snappy.parquet
-rw-r--r-- 1 root root 421 Dec 1 01:54 part-00003-4d5a3a89-2995-4328-b2ae-908febbbaf4a-c000.snappy.parquet
-rw-r--r-- 1 root root 421 Dec 1 01:54 part-00004-4d5a3a89-2995-4328-b2ae-908febbbaf4a-c000.snappy.parquet
-rw-r--r-- 1 root root 421 Dec 1 01:54 part-00005-4d5a3a89-2995-4328-b2ae-908febbbaf4a-c000.snappy.parquet
-rw-r--r-- 1 root root 421 Dec 1 01:54 part-00006-4d5a3a89-2995-4328-b2ae-908febbbaf4a-c000.snappy.parquet
-rw-r--r-- 1 root root 421 Dec 1 01:54 part-00007-4d5a3a89-2995-4328-b2ae-908febbbaf4a-c000.snappy.parquet
-rw-r--r-- 1 root root 0 Dec 1 01:54 _SUCCESS
```
After this pr and set `spark.sql.files.minPartitionNum` to 1:
```
-rw-r--r-- 1 root root 452 Dec 1 01:59 part-00000-6de50c79-e305-4f8d-b6ae-39f46b2619c6-c000.snappy.parquet
-rw-r--r-- 1 root root 0 Dec 1 01:59 _SUCCESS
```
### Does this PR introduce _any_ user-facing change?
No.
### How was this patch tested?
Unit test.
Closes#30559 from wangyum/SPARK-33617.
Lead-authored-by: Yuming Wang <yumwang@ebay.com>
Co-authored-by: Yuming Wang <yumwang@apache.org>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
1e0c006748