[Snackbar] Add multiline support

[treylon]

It would be great if the Snackbar would support multiline texts. The specs for Snackbar multiline support can be found here:
https://www.google.com/design/spec/components/snackbars-toasts.html#snackbars-toasts-specs

This feature has already been mentioned here #2826 by @mbrookes
Do you think you could fold in this little change in one of the following releases?

[mbrookes]

@treylon, @rynti, this looks like the kind of thing you should be able to tackle as a PR, since Snackbar is a relatively simple component. Feel free to give it a go if this feature is important to you.

[treylon]

@mbrookes I'll tackle it in the next few days :)

[mauliksoni110]

Is there any update on this?

[DesignMonkey]

You can archive it with styling like

const message = 'First line\nSecond Line'

...

<Snackbar
  message={message}        
  bodyStyle={{ height: 'auto', lineHeight: '28px', padding: 24, whiteSpace: 'pre-line' }}
/>

Maybe try and set a maxHeight for mobile devices.