Sponsorship integration

Description

Allow users to become sponsors of VLC Android by doing a one-time or recurrent payment.

Motivation and Context

How Has This Been Tested?

Screenshots / GIFs (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Enhancement (non-breaking change which cleans up / improves existing functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• I have read the CONTRIBUTING section of the README document.

Resolves

Fixes: # Mention: #