Remove Change Navigation Mode option for Taskbar Divider Popup Menu

- Breakout CL part 3
- This is a breakout cl from ag/24272821 to make it more readable and atomic.
- This cl consist removal of an option from taskbar divider popup meu which is no longer required and other changes regarding the removal like ripple.

Test: Manual, Visual
Bug: 265170176
Flag: ENABLE_TASKBAR_PINNING
Change-Id: I3664df7a134cc0eb5b4ed856c7e0730ef1b75dea