spanner: Fix use of in-memory sequence generator (#103767)

pkg/util/xorm/dialect_spanner.go

@@ -383,7 +383,7 @@ func (s *spanner) CreateSequenceGenerator(db *sql.DB) (SequenceGenerator, error)
 		return nil, err
 	}
 
-	if connectorConfig.Params["inMemSequenceGenerator"] == "true" {
+	if connectorConfig.Params[strings.ToLower("inMemSequenceGenerator")] == "true" {
 		// Switch to using in-memory sequence number generator.
 		// Using database-based sequence generator doesn't work with emulator, as emulator
 		// only supports single transaction. If there is already another transaction started