Bouncy text entry in landscape on 4" screens

Type in the note editor when in landscape on a 4" screen (like iPhone 5), and observe how the text jumps around like crazy.

@jleandroperez "After an epic round of hacks, i've traced this bug down to this line.

Apparently, the content insets we're using is what's causing the bounce effect. Still digging into why this is happening, + workarounds!"

t-O62108

Opened by @roundhill

Reproduce the bounce in the note editor on a 4-inch iPhone-sized screen in landscape while typing. Investigate the content insets mentioned in the issue and determine why they cause the text to jump; done means landscape text entry no longer bounces on that screen size. No source file or test is named, and the issue has had no recent activity.

Written by the indexing model from the issue text.