[iOS 13] Modal lazy loaded background is transparent on iOS 13 #2012

Environment
Provide version numbers for the following components (information can be retrieved by running tns info in your project folder or by inspecting the package.json of the project):

• CLI: 6.*
• Cross-platform modules: 6.*
• Android Runtime: 6.*
• iOS Runtime: 6.*

Describe the bug
The example Lazy loaded via modal is different on iOS 13 than on iOS 12. The modal dialog background is transparent instead of white.

To Reproduce

1. Run the tests-app-ng app in this repo on iOS 13.
2. Navigate to Modal -> lazy
3. Tap on "Load modal!" label

Expected behavior
The modal should hide the page and its background should be transparent.

Actual
The modal is transparent and content behind is visible.

Sample project
tests-app-ng application in this repo

Additional context
The difference between iOS 12 and 13 is that this modal can be swiped down on iOS 13.