[native][web] Merge logout buttons for old and new flows

Summary:
Address ENG-9688.

• Removed the experimental buttons for new logout flows
• Main logout button behavior depends on usingRestoreFlow:
  • legacy logout (current behavior) if false
  • Primary/secondary logout if true

Depends on D14146

Test Plan: Changed the flag true/false and pressed logout button. Made sure correct procedure is executed

Reviewers: kamil, tomek

Reviewed By: kamil

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D14147