Client does not respect Message Retention

### Steps to reproduce

1. Configure the `retention` section for your Matrix Home Server.
2. Write messages
3. After the `retention.default_policy.max_lifetime` is exceeded the Messages are still present

In my case the server has the following configuration set for retention:

```yaml
retention:
enabled: true
default_policy:
min_lifetime: 1d
max_lifetime: 30d
allowed_lifetime_min: 1d
allowed_lifetime_max: 180d
```

### Outcome

#### What did you expect?

Client respects the default retention settings from the Home Server.

#### What happened instead?

Settings seems to be ignored.

### Your phone model

iPhone 12 Pro

### Operating system version

iOS 15.1.1

### Application version

1.6.8

### Homeserver

matrix.systemli.org

### Will you send logs?

No

Start by reproducing this in the iOS app with a Matrix homeserver configured with retention.enabled and default_policy.max_lifetime, then inspect how the client handles messages after that lifetime expires. Done means messages are no longer shown once the homeserver's retention policy removes them; the issue names no source files or tests to begin from.

Written by the indexing model from the issue text.