A11y fix for all widgets tray (Part 2 / n)

Fix the focus change when expanding / collapsing an app in
the all widgets tray by adding stable ids and disable item
animator.

Item animator is also disable even accessibility isn't enabled
because the default item animator also disrupts the header
padding. It also makes the expansion / collapsing of widgets table
very unpredicible.

Test: Navigate all widgets tray with talkback on.

Bug: 183120145
Change-Id: Ib1e2ea4d543757248e635a834204db688532cbfa