Handle OnDismiss event on option dialogs

Description

This fixes the nav bar not dimmed when an option dialog is closed in VideoPlayer, such as BottomSheets or track selection.

Motivation and Context

How Has This Been Tested?

Sony Xperia XZ2 & Shield Tablet K1

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