Gif block styles conflict with theme block styles

When I embed the Jetpack gif block it does not honor the themes margin properties. In particular when I set the block to alignfull. The alignfull margin in the theme is set to have a negative left margin so that the content can stretch full width, but the gif block overrides this value.

I would suggest making the margin in the block less specific.

If you change this line:
https://github.com/Automattic/jetpack/blob/fcf029c3deb172b4982f2a9d964b999aab1aa438/extensions/blocks/gif/style.scss#L5

So that it is: `margin-bottom: 20px;` then my negative side margins will still work.

Thanks - Ben

Start with extensions/blocks/gif/style.scss at the linked line and inspect how its margin declaration interacts with the theme's alignfull styles. Verify the GIF block in an alignfull theme layout, and consider the issue complete when the theme's negative side margins are preserved while the block's bottom spacing remains correct.

Written by the indexing model from the issue text.