Make all apps text focusable by accessibility.

From b/330638194, the requirement is that
1. "all apps" can be focusable with talkback
2. "all apps" text is persisted when in accessibility mode.

Merged-In:Ibabb92bd9d202221fdc9cfacb585755167898187
bug:330638194
Test: manual video: https://drive.google.com/file/d/1QI_F4dUijfnU2ahE2Mg6yrmRJfOVyuVJ/view?usp=sharing
Flag: None

Change-Id: Ibabb92bd9d202221fdc9cfacb585755167898187