[BACKPORT 2.20.2][PLAT-13161]: Fix restore autoflag check

Summary:
While fetching autoflags on target universe, we were extracting master autoflags instead of tserver autoflags while comparing tserverautoflags of backup.
original diff/commit: D33268

Test Plan: Tested manually by creating 2 universe, where one universe has ysql_enable_packed_row in disabled state, so the restore is expected to fail but after setting it on other universe through gflags upgrade, restore passes.

Reviewers: svarshney

Reviewed By: svarshney

Subscribers: yugaware

Tags: #jenkins-ready

Differential Revision: https://phorge.dev.yugabyte.com/D33276

managed/src/main/java/com/yugabyte/yw/common/backuprestore/ybc/YbcBackupUtil.java

@@ -1005,7 +1005,7 @@ public boolean validateAutoFlagCompatibility(
       Set<String> targetTServerAutoFlags =
           autoFlagUtil.getPromotedAutoFlags(
               universe,
-              UniverseTaskBase.ServerType.MASTER,
+              UniverseTaskBase.ServerType.TSERVER,
               AutoFlagUtil.LOCAL_PERSISTED_AUTO_FLAG_CLASS);
       for (String flag : tserverAutoFlags) {
         if (GFlagsValidation.TEST_AUTO_FLAGS.contains(flag)) {