Pull request

Description

This PR updates the Google Cast showcase to display the media artwork while casting.

Changes made

• Update the Google Cast showcase to display the media artwork while casting.
• If no artwork is available, or if it can't be loaded, a default artwork is used.
• Use the Cast icon from MediaRouter as a fallback, instead of using our own icon.
• Disable the support library for vector drawable parsing (we don't have any vector drawable in pillarbox-demo).

Checklist

• APIs have been properly documented (if relevant).
• The documentation has been updated (if relevant).
• New unit tests have been written (if relevant).
• The demo has been updated (if relevant).