Window can be partly behind toolbar

[JJK96]

https://imgur.com/gxFvMpZ

Both windows have the same content and are scrolled all the way up.
It is clear that there is more space between the toolbar and the title in the lower window.

The window size is probably calculated wrongly.

Bug was found on And Bible version
Build 42b6db8

To Reproduce
Steps to reproduce the behavior:

1. Open two windows
2. Scroll them to the top
3. Observe the difference

Expected behavior
Both windows should behave the same.

Smartphone (please complete the following information):

• Device: Oneplus 6
• OS: Android
• Version 10

Additional context
I ran into this issue while working on #188, I can display the notes, but the top part of the text can be hidden behind the toolbar.

[JJK96]

This seems to be intentional in order to have nice transitions to fullscreen.

[tuomas2]

I think it still would be good to prevent split bar from going under toolbar / system bars.

[tuomas2]

Indeed this is practically duplicate of #509

[JJK96]

Maybe there's a better way to have smooth transition to fullscreen while the main window is not underneath the toolbar.

That would solve this problem, and also #509.