[SPARK-30556][SQL][FOLLOWUP] Reset the status changed in SQLExecution.withThreadLocalCaptured

### What changes were proposed in this pull request?
Follow up for #27267, reset the status changed in SQLExecution.withThreadLocalCaptured.

### Why are the changes needed?
For code safety.

### Does this PR introduce any user-facing change?
No.

### How was this patch tested?
Existing UT.

Closes #27516 from xuanyuanking/SPARK-30556-follow.

Authored-by: Yuanjian Li <[email protected]>
Signed-off-by: herman <[email protected]>

Author: xuanyuanking

sql/core/src/main/scala/org/apache/spark/sql/execution/SQLExecution.scala

@@ -177,9 +177,19 @@ object SQLExecution {
     val sc = sparkSession.sparkContext
     val localProps = Utils.cloneProperties(sc.getLocalProperties)
     Future {
+      val originalSession = SparkSession.getActiveSession
+      val originalLocalProps = sc.getLocalProperties
       SparkSession.setActiveSession(activeSession)
       sc.setLocalProperties(localProps)
-      body
+      val res = body
+      // reset active session and local props.
+      sc.setLocalProperties(originalLocalProps)
+      if (originalSession.nonEmpty) {
+        SparkSession.setActiveSession(originalSession.get)
+      } else {
+        SparkSession.clearActiveSession()
+      }
+      res
     }(exec)
   }
 }

sql/core/src/test/scala/org/apache/spark/sql/internal/ExecutorSideSQLConfSuite.scala

@@ -17,6 +17,8 @@
 
 package org.apache.spark.sql.internal
 
+import java.util.UUID
+
 import org.scalatest.Assertions._
 
 import org.apache.spark.{SparkException, SparkFunSuite, TaskContext}
@@ -144,16 +146,16 @@ class ExecutorSideSQLConfSuite extends SparkFunSuite with SQLTestUtils {
         }
 
         // set local configuration and assert
-        val confValue1 = "e"
+        val confValue1 = UUID.randomUUID().toString()
         createDataframe(confKey, confValue1).createOrReplaceTempView("m")
         spark.sparkContext.setLocalProperty(confKey, confValue1)
-        assert(sql("SELECT * FROM l WHERE EXISTS (SELECT * FROM m)").collect.size == 1)
+        assert(sql("SELECT * FROM l WHERE EXISTS (SELECT * FROM m)").collect().length == 1)
 
         // change the conf value and assert again
-        val confValue2 = "f"
+        val confValue2 = UUID.randomUUID().toString()
         createDataframe(confKey, confValue2).createOrReplaceTempView("n")
         spark.sparkContext.setLocalProperty(confKey, confValue2)
-        assert(sql("SELECT * FROM l WHERE EXISTS (SELECT * FROM n)").collect().size == 1)
+        assert(sql("SELECT * FROM l WHERE EXISTS (SELECT * FROM n)").collect().length == 1)
       }
     }
   }