[consensus] trigger sync based on remote LI timestamp

consensus/src/block_storage/sync_manager.rs

@@ -68,6 +68,13 @@ impl BlockStore {
             && !self.block_exists(li.commit_info().id()))
             || self.commit_root().round() + 30.max(2 * self.vote_back_pressure_limit)
                 < li.commit_info().round()
+            // If the LI commit block timestamp is more than 30 secs ahead of self commit block
+            // timestamp, sync to the ledger info
+            || li
+                .commit_info()
+                .timestamp_usecs()
+                .saturating_sub(self.commit_root().timestamp_usecs())
+                >= Duration::from_secs(30).as_micros() as u64
     }
 
     /// Checks if quorum certificate can be inserted in block store without RPC