Fix test_protocol_upgrade_under_congestion

This test kept failing on the check:
```
assert!(congestion_info.receipt_bytes() > next_congestion_info.receipt_bytes());
```

It seems flaky, sometimes it passes and sometimes it doesn't.
I think it's related to the recent changes (tx and receipt size limits).

Let's change the way in which we test that the chain is doing progress
to measuring burned gas on the congested shard, this is more reliable
and makes the test pass.

integration-tests/src/tests/client/features/congestion_control.rs

@@ -1,4 +1,5 @@
 use assert_matches::assert_matches;
+use near_chain::Provenance;
 use near_chain_configs::Genesis;
 use near_client::test_utils::TestEnv;
 use near_client::ProcessTxResponse;
@@ -212,11 +213,19 @@ fn test_protocol_upgrade_under_congestion() {
     );
 
     // Also check that the congested shard is still making progress.
-    env.produce_block(0, tip.height + 1);
-    let next_congestion_info = head_congestion_info(&mut env, contract_shard_id);
+    let block = env.clients[0].produce_block(tip.height + 1).unwrap().unwrap();
+    assert_eq!(
+        block.header().chunk_mask()[contract_shard_id as usize],
+        true,
+        "chunk isn't missing"
+    );
+    let gas_used = block.chunks().get(contract_shard_id as usize).unwrap().prev_gas_used();
+    tracing::debug!(target: "test", "prev_gas_used: {}", gas_used);
+
+    // The chunk should process at least 500TGas worth of receipts
+    assert!(gas_used > 500_000_000_000_000);
 
-    assert!(congestion_info.delayed_receipts_gas() > next_congestion_info.delayed_receipts_gas());
-    assert!(congestion_info.receipt_bytes() > next_congestion_info.receipt_bytes());
+    env.process_block(0, block, Provenance::PRODUCED);
 }
 
 /// Check we are still in the old version and no congestion info is shared.