Do not attach tiny taskbar to app during transition.

Navigation bar is normally supposed to attach to the app for this
transition, but tiny taskbar should remain fixed to the bottom of the
screen.

Flag: com.android.wm.shell.enable_tiny_taskbar
Test: Manual
Bug: 341784466
Change-Id: I0f10a524975663c0ada0661d64daffac6a7c69ca