iOS: set modalPresentationStyle to fullscreen

[IcoDeveloper]

Description

On iOS version 13 or greater it was possible to dismiss scanner overlay through swiping without getting a cancel response in callback. This causes an unresolved promise and a stuck application.
To prevent this I have reset modalPresentationStyle to fullscreen which was the default setting in iOS12.

Type of change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Self-tested on real iPhone with iOS 14.5 installed.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules