Add full screen activity

[mjcctech]

Description

Add full screen activity

Related Issue

Motivation and Context

I had problem with wakening up Samsung phones. When phone is in dose mode notification is received but screen stay off and only sound is played. My requirement is to catch user attention.

How Has This Been Tested?

In payload add

'full-screen-notification': '1'

Screenshots (if appropriate):

Types of changes

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

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[rhapsodyv]

Any plans to merge this?
Thanks!

[Qvadis]

This would be nice, any updates on this?