Scrolling broken on long posts while input has keyboard focus

[guarani]

Describe the bug
If an input has keyboard focus, scrolling through large posts it's sometimes impossible to scroll far before the scroll position is reset. It appears that the scroll is reset sometime after the focused input goes off-screen.

To Reproduce

1. Open the demo Gutenberg Android app showing the default content
2. Scroll down to the bottom and put keyboard focus in a Paragraph or other focusable block
3. Start scrolling up to the top of the editor content and notice that soon after the focusable block is no longer on-screen, the editor moves the scroll position back down so it's nearly impossible to scroll to the top of a post

Expected behavior
A clear and concise description of what you expected to happen.

Screenshots

Smartphone (please complete the following information):

• Device: Samsung S10
• OS: Android 10
• Version: WordPress/gutenberg@40a5502

Additional context
The workaround to scroll to the top of a long post is to first ensure that no input has keyboard focus.

[mzorz]

I also noticed this issue with cursor positioning with the this test post: when a paragraph block is selected and the cursor is blinking there, scrolling out of it is super hard. I tried scrolling all the way up and the editor insists in bringing focus to the selected block. Found out this while trying to reproduce and investigate the issue tracked in wordpress-mobile/WordPress-Android#13361

[guarani]

Noting this is still reproducible on the latest Gutenberg trunk, WordPress/gutenberg@50618d5.