[SPARK-23852][SQL] Add withSQLConf(...) to test case

## What changes were proposed in this pull request?

Add a `withSQLConf(...)` wrapper to force Parquet filter pushdown for a test that relies on it.

## How was this patch tested?

Test passes

Author: Henry Robinson <[email protected]>

Closes #21323 from henryr/spark-23582.

sql/core/src/test/scala/org/apache/spark/sql/execution/datasources/parquet/ParquetFilterSuite.scala

@@ -650,13 +650,15 @@ class ParquetFilterSuite extends QueryTest with ParquetTest with SharedSQLContex
   }
 
   test("SPARK-23852: Broken Parquet push-down for partially-written stats") {
-    // parquet-1217.parquet contains a single column with values -1, 0, 1, 2 and null.
-    // The row-group statistics include null counts, but not min and max values, which
-    // triggers PARQUET-1217.
-    val df = readResourceParquetFile("test-data/parquet-1217.parquet")
+    withSQLConf(SQLConf.PARQUET_FILTER_PUSHDOWN_ENABLED.key -> "true") {
+      // parquet-1217.parquet contains a single column with values -1, 0, 1, 2 and null.
+      // The row-group statistics include null counts, but not min and max values, which
+      // triggers PARQUET-1217.
+      val df = readResourceParquetFile("test-data/parquet-1217.parquet")
 
-    // Will return 0 rows if PARQUET-1217 is not fixed.
-    assert(df.where("col > 0").count() === 2)
+      // Will return 0 rows if PARQUET-1217 is not fixed.
+      assert(df.where("col > 0").count() === 2)
+    }
   }
 }