sql: set GLOBAL on MATERIALIZED VIEW tables on first ADD REGION

Release note (sql change): Materialized views which are in a database
before the first ADD REGION will become GLOBAL on ADD REGION, in line
with the behavior of CREATE MATERIALIZED VIEW on a multi-region
database.

pkg/ccl/logictestccl/testdata/logic_test/multi_region

@@ -1320,7 +1320,8 @@ statement ok
 CREATE TABLE t (id INT PRIMARY KEY, a INT, b INT);
 INSERT INTO t VALUES (1, 2, 3), (4, 5, 6);
 CREATE SEQUENCE s;
-CREATE VIEW v AS SELECT id, a, b FROM t
+CREATE VIEW v AS SELECT id, a, b FROM t;
+CREATE MATERIALIZED VIEW mat_view AS SELECT id, a, b FROM t
 
 statement ok
 ALTER DATABASE db_with_views_and_sequences SET PRIMARY REGION "ap-southeast-2"
@@ -1332,6 +1333,7 @@ table_name  locality
 t           REGIONAL BY TABLE IN PRIMARY REGION
 s           REGIONAL BY TABLE IN PRIMARY REGION
 v           REGIONAL BY TABLE IN PRIMARY REGION
+mat_view    GLOBAL
 
 statement ok
 CREATE SEQUENCE s2;
@@ -1345,6 +1347,7 @@ table_name  locality
 t           REGIONAL BY TABLE IN PRIMARY REGION
 s           REGIONAL BY TABLE IN PRIMARY REGION
 v           REGIONAL BY TABLE IN PRIMARY REGION
+mat_view    GLOBAL
 s2          REGIONAL BY TABLE IN PRIMARY REGION
 v2          REGIONAL BY TABLE IN PRIMARY REGION
 mat_view2   GLOBAL
@@ -1373,6 +1376,7 @@ table_name  locality
 t           NULL
 s           NULL
 v           NULL
+mat_view    NULL
 s2          NULL
 v2          NULL
 mat_view2   NULL

pkg/sql/alter_database.go

@@ -588,10 +588,18 @@ func addDefaultLocalityConfigToAllTables(
 				return err
 			}
 
-			if err := p.alterTableDescLocalityToRegionalByTable(
-				ctx, tree.PrimaryRegionNotSpecifiedName, mutDesc, regionEnumID,
-			); err != nil {
-				return err
+			if mutDesc.MaterializedView() {
+				if err := p.alterTableDescLocalityToGlobal(
+					ctx, mutDesc, regionEnumID,
+				); err != nil {
+					return err
+				}
+			} else {
+				if err := p.alterTableDescLocalityToRegionalByTable(
+					ctx, tree.PrimaryRegionNotSpecifiedName, mutDesc, regionEnumID,
+				); err != nil {
+					return err
+				}
 			}
 
 			if err := p.writeSchemaChangeToBatch(ctx, mutDesc, b); err != nil {