Using "TouchScreenKeyboard.Open()" doesn't open touch screen keyboard on Windows 10 tablet, when using "tablet mode". Regression from 5.2.0f3.

Issue reproducible only on UWP platform. Tested versions: 5.2.1, 5.2.2f1, 5.2.3f1, 5.3.0f1.

Important part: if application was deployed from 5.2.0f3 version, further versions will work fine (touch screen keyboard will open). You need to uninstall previous application version to get the correct results.

WSA 8.1 platform works fine.

repro steps:
1. open "wsa_keyboard.zip" project;
2. build to Universal 10 platform;
3. set your Windows 10 tablet to tablet mode. Deploy application on tablet.
4. press "open keyboard".