Set camera icon as gray when app is unlaunchable

This CL is a follow-up to ag/26825455. Now that we are changing app pairs' disabled appearance back to icon-only, the case where a camera icon should be grayed out on an app pair on a small screen needs to be reinstated.

Fixes: 333137187
Flag: ACONFIG com.android.wm.shell.enable_app_pairs TRUNKFOOD
Test: Manual
Change-Id: I64ae3db28293fa0adc249d700e9e03c074b6854f