#2107 clarify accessibility restart dialog copy and actions

[keymapper-ai]

Summary

• update the crashed accessibility restart dialog text to explicitly instruct turning the service off and on again
• simplify the restart dialog actions to only Cancel and Restart
• keep existing restart wiring and fallback behavior unchanged

Test plan

• trigger the crashed accessibility warning and tap Fix
• verify the dialog copy explains turning accessibility off and on
• verify only Cancel and Restart actions are shown
• verify tapping Restart still follows existing restart behavior