chore: update deafult mempool size to match ttl and block size (backp…

…ort #2681) (#2685)

This is an automatic backport of pull request #2681 done by
[Mergify](https://mergify.com).


---


<details>
<summary>Mergify commands and options</summary>

<br />

More conditions and actions can be found in the
[documentation](https://docs.mergify.com/).

You can also trigger Mergify actions by commenting on this pull request:

- `@Mergifyio refresh` will re-evaluate the rules
- `@Mergifyio rebase` will rebase this PR on its base branch
- `@Mergifyio update` will merge the base branch into this PR
- `@Mergifyio backport <destination>` will backport this PR on
`<destination>` branch

Additionally, on Mergify [dashboard](https://dashboard.mergify.com) you
can:

- look at your merge queues
- generate the Mergify configuration with the config editor.

Finally, you can contact us on https://mergify.com
</details>

Co-authored-by: Evan Forbes <42654277+evan-forbes@users.noreply.github.com>

app/default_overrides.go

@@ -225,6 +225,7 @@ func DefaultConsensusConfig() *tmcfg.Config {
 	// version. This acts as a first line of DoS protection
 	upperBoundBytes := appconsts.DefaultSquareSizeUpperBound * appconsts.DefaultSquareSizeUpperBound * appconsts.ContinuationSparseShareContentSize
 	cfg.Mempool.MaxTxBytes = upperBoundBytes
+	cfg.Mempool.MaxTxsBytes = int64(upperBoundBytes) * cfg.Mempool.TTLNumBlocks
 
 	cfg.Mempool.Version = "v1" // prioritized mempool
 	cfg.Consensus.TimeoutPropose = appconsts.TimeoutPropose