Revert "[SPARK-35028][SQL] ANSI mode: disallow group by aliases"

### What changes were proposed in this pull request?

Revert [[SPARK-35028][SQL] ANSI mode: disallow group by aliases ](https://github.com/apache/spark/pull/32129)

### Why are the changes needed?

It turns out that many users are using the group by alias feature.  Spark has its precedence rule when alias names conflict with column names in Group by clause: always use the table column. This should be reasonable and acceptable.
Also, external DBMS such as PostgreSQL and MySQL allow grouping by alias, too.

As we are going to announce ANSI mode GA in Spark 3.2, I suggest allowing the group by alias in ANSI mode.

### Does this PR introduce _any_ user-facing change?

No, the feature is not released yet.

### How was this patch tested?

Unit tests

Closes #33758 from gengliangwang/revertGroupByAlias.

Authored-by: Gengliang Wang <gengliang@apache.org>
Signed-off-by: Gengliang Wang <gengliang@apache.org>

docs/sql-ref-ansi-compliance.md

@@ -255,7 +255,6 @@ The behavior of some SQL functions can be different under ANSI mode (`spark.sql.
 The behavior of some SQL operators can be different under ANSI mode (`spark.sql.ansi.enabled=true`).
   - `array_col[index]`: This operator throws `ArrayIndexOutOfBoundsException` if using invalid indices.
   - `map_col[key]`: This operator throws `NoSuchElementException` if key does not exist in map.
-  - `GROUP BY`: aliases in a select list can not be used in GROUP BY clauses. Each column referenced in a GROUP BY clause shall unambiguously reference a column of the table resulting from the FROM clause.
 
 ### Useful Functions for ANSI Mode
 

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/Analyzer.scala

@@ -1948,7 +1948,7 @@ class Analyzer(override val catalogManager: CatalogManager)
       // mayResolveAttrByAggregateExprs requires the TreePattern UNRESOLVED_ATTRIBUTE.
       _.containsAllPatterns(AGGREGATE, UNRESOLVED_ATTRIBUTE), ruleId) {
       case agg @ Aggregate(groups, aggs, child)
-          if allowGroupByAlias && child.resolved && aggs.forall(_.resolved) &&
+          if conf.groupByAliases && child.resolved && aggs.forall(_.resolved) &&
             groups.exists(!_.resolved) =>
         agg.copy(groupingExpressions = mayResolveAttrByAggregateExprs(groups, aggs, child))
     }

sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala

@@ -240,17 +240,6 @@ object SQLConf {
     .intConf
     .createWithDefault(100)
 
-  val ANSI_ENABLED = buildConf("spark.sql.ansi.enabled")
-    .doc("When true, Spark SQL uses an ANSI compliant dialect instead of being Hive compliant. " +
-      "For example, Spark will throw an exception at runtime instead of returning null results " +
-      "when the inputs to a SQL operator/function are invalid." +
-      "For full details of this dialect, you can find them in the section \"ANSI Compliance\" of " +
-      "Spark's documentation. Some ANSI dialect features may be not from the ANSI SQL " +
-      "standard directly, but their behaviors align with ANSI SQL's style")
-    .version("3.0.0")
-    .booleanConf
-    .createWithDefault(false)
-
   val OPTIMIZER_EXCLUDED_RULES = buildConf("spark.sql.optimizer.excludedRules")
     .doc("Configures a list of rules to be disabled in the optimizer, in which the rules are " +
       "specified by their rule names and separated by comma. It is not guaranteed that all the " +
@@ -1221,9 +1210,8 @@ object SQLConf {
     .createWithDefault(true)
 
   val GROUP_BY_ALIASES = buildConf("spark.sql.groupByAliases")
-    .doc("This configuration is only effective when ANSI mode is disabled. When it is true and " +
-      s"${ANSI_ENABLED.key} is false, aliases in a select list can be used in group by clauses. " +
-      "Otherwise, an analysis exception is thrown in the case.")
+    .doc("When true, aliases in a select list can be used in group by clauses. When false, " +
+      "an analysis exception is thrown in the case.")
     .version("2.2.0")
     .booleanConf
     .createWithDefault(true)
@@ -2547,6 +2535,17 @@ object SQLConf {
       .checkValues(StoreAssignmentPolicy.values.map(_.toString))
       .createWithDefault(StoreAssignmentPolicy.ANSI.toString)
 
+  val ANSI_ENABLED = buildConf("spark.sql.ansi.enabled")
+    .doc("When true, Spark SQL uses an ANSI compliant dialect instead of being Hive compliant. " +
+      "For example, Spark will throw an exception at runtime instead of returning null results " +
+      "when the inputs to a SQL operator/function are invalid." +
+      "For full details of this dialect, you can find them in the section \"ANSI Compliance\" of " +
+      "Spark's documentation. Some ANSI dialect features may be not from the ANSI SQL " +
+      "standard directly, but their behaviors align with ANSI SQL's style")
+    .version("3.0.0")
+    .booleanConf
+    .createWithDefault(false)
+
   val SORT_BEFORE_REPARTITION =
     buildConf("spark.sql.execution.sortBeforeRepartition")
       .internal()

sql/core/src/test/resources/sql-tests/inputs/ansi/group-analytics.sql

@@ -1 +0,0 @@
---IMPORT group-analytics.sql