Add on/off state description to mode tile toggles.

This allows screen readers to read the state of the button, and react to presses that change it.

The description now reads "[on/off], [mode name], [trigger description]" similarly to how other quick settings tiles behave.

Also adds long click label so it will read "double tap and hold to open settings".

Bug: 359845144
Test: manual with TalkBack, ModesDialogViewModelTest
Flag: android.app.modes_ui
Change-Id: Icb31b77ebe31e607fde87eb51356ea27bafc9278