[yugabyte#24625] YSQL: Rename TestPgRegressGenerated class

Summary:
Rename TestPgRegressGenerated to TestPgRegressPgGenerated to keep it consistent with other child classes of BasePgRegressTestPorted.
Jira: DB-13679

Test Plan: Jenkins: test regex: TestPgRegressPgGenerated*

Reviewers: stiwary

Reviewed By: stiwary

Subscribers: yql

Differential Revision: https://phorge.dev.yugabyte.com/D39461

java/yb-pgsql/src/test/java/org/yb/pgsql/TestPgRegressGenerated.java → java/yb-pgsql/src/test/java/org/yb/pgsql/TestPgRegressPgGenerated.java

@@ -20,7 +20,7 @@
  * Runs the pg_regress test suite on YB code.
  */
 @RunWith(value=YBTestRunner.class)
-public class TestPgRegressGenerated extends BasePgRegressTestPorted {
+public class TestPgRegressPgGenerated extends BasePgRegressTestPorted {
   @Override
   public int getTestMethodTimeoutSec() {
     return 1800;