[a11y] Change all apps screen name to All Apps instead of reusing Home.

Now even when we enter the All Apps page, talkback still reads the page name as Home (https://source.corp.google.com/h/googleplex-android/platform/superproject/main/+/main:packages/apps/Launcher3/src/com/android/launcher3/Launcher.java;l=586;drc=120838b04dcaf072704c6fb382ea9115672cfcaa).

Bug: 330470894
Bug: 333833220
Test: manual
Flag: NA
Change-Id: I32a1ce8844cd111c7d1c492ee0a39fec47858a47