Support embedding Mobile Twitter URLs

[dpcalhoun]

When embedding a mobile variant of a Tweet URL, the Gutenberg Embed block considers the URL to be an invalid embed.

Steps to Reproduce

1. Add an Embed block via the web or native mobile Gutenberg block editor.
2. Set the Embed block URL to a mobile Twitter URL: ​https://mobile.twitter.com/rauchg/status/807626710350839808
3. Save the Embed block settings, persisting the URL.

Expected Result

The Embed block displays a preview of the Tweet as an embed.

Actual Result

The Embed block marks the URL as invalid, resulting in a error message or a plain text URL.

Related

• ​Gutenberg Issue
• ​Relevant oembed code
• oEmbed API response message:

  {
      "code": "oembed_invalid_url",
      "message": "Not Found",
      "data": {
          "status": 404
      }
  }
  

Environment

• WordPress: 5.8.1
• Theme: Twenty Twenty-One
• Plugins: none
• Browser: macOS Safari 15.1