Message with msgtype = m.notice renders like regular message

### Steps to reproduce

1. observe how a `m.notice` message is rendered in a timeline

### Outcome

#### What did you expect?

It should render differently than regular messages.

#### What happened instead?

`m.notice` are rendered as regular messages.

Note: EX iOS is rendering a `info` picto on the left of the message, but I can't find any design about this. Element Web is rendering `m.notice` using secondary text color. @amshakal can you help please?

### Your phone model

any

### Operating system version

any

### Application version and app store

all

### Homeserver

any

### Will you send logs?

No

### Are you willing to provide a PR?

Yes

Start by tracing how m.notice messages are rendered in the Android timeline, then compare the available Element Web and EX iOS behavior. The issue does not specify an approved design, so confirm the intended visual treatment before changing anything; done means m.notice is visibly distinct from regular messages and the behavior is covered by an appropriate test.

Written by the indexing model from the issue text.