Add developer option to tweak All Apps from Overview threshold.

Ability to move threshold from shift 1.05 to 5.0. Saved as an int
from 105 to 500. Shift 1.0 is where Overview rests; using this
value exactly causes a slight glitch while settling.

Demo (slightly outdated min value and flavor text):
https://drive.google.com/file/d/1PaS4MjFM1P9ZHQ-400tXUbDz_-z8qYtC/view?usp=drive_link&resourcekey=0-ZX-ofW4AzN0-Qjqo4OmU-g

Bug: 281717218
Test: Manual
Flag: ENABLE_ALL_APPS_FROM_OVERVIEW
Change-Id: I5acfb46f9df16e9d3091a7822c449301bc6067f9