Set All Apps scale to 1 to start.

This avoids a bug on the first back gesture in All Apps from
search back to the A-Z list, where the apps scaled to 0-1 quickly
as part of the reset logic added in ag/21182334.

Bug: 269541162
Test: Install launcher, open all apps, tap search bar, go back.
Change-Id: I0dbd7275a80b585acf6f05ef1ef25c7c47f59ff6