[BACKPORT 2.20.5][#22984] CDCSDK: Promote yb_enable_cdc_consistent_sn…

…apshot_streams to auto flag

Summary:
Original commit: 9656a89 / D36084

This diff promotes the flag yb_enable_cdc_consistent_snapshot_streams from a preview flag to a default true auto flag.

######Backport Description
Merge conflicts were encountered due to the fact that the definition of yb_enable_cdc_consistent_snapshot_streams has been moved from src/yb/master/xrepl_catalog_manager.cc to src/yb/common/common_flags.cc in latest master.
Jira: DB-11902

Test Plan: Jenkins: rebase 2.20.5

Reviewers: asrinivasan, skumar, stiwary

Reviewed By: asrinivasan

Subscribers: ycdcxcluster

Tags: #jenkins-ready

Differential Revision: https://phorge.dev.yugabyte.com/D36089

src/yb/integration-tests/cdcsdk_consistent_snapshot-test.cc

@@ -21,7 +21,6 @@ class CDCSDKConsistentSnapshotTest : public CDCSDKYsqlTest {
  public:
   void SetUp() override {
     CDCSDKYsqlTest::SetUp();
-    ANNOTATE_UNPROTECTED_WRITE(FLAGS_yb_enable_cdc_consistent_snapshot_streams) = true;
     ANNOTATE_UNPROTECTED_WRITE(FLAGS_enable_tablet_split_of_cdcsdk_streamed_tables) = true;
 
     // Disable pg replication command support to ensure that consistent snapshot feature

src/yb/master/xrepl_catalog_manager.cc

@@ -126,8 +126,9 @@ DEFINE_test_flag(
     bool, allow_ycql_transactional_xcluster, false,
     "Determines if xCluster transactional replication on YCQL tables is allowed.");
 
-DEFINE_RUNTIME_PREVIEW_bool(yb_enable_cdc_consistent_snapshot_streams, false,
-                            "Enable support for CDC Consistent Snapshot Streams");
+DEFINE_RUNTIME_AUTO_bool(
+    yb_enable_cdc_consistent_snapshot_streams, kLocalPersisted, false, true,
+    "Enable support for CDC Consistent Snapshot Streams");
 
 DEFINE_test_flag(bool, fail_universe_replication_merge, false, "Causes MergeUniverseReplication to "
     "fail with an error.");