autoclick: Alert user to use 3-button navigation

Autoclick works best with 3-button gesture, when Autoclick is turned on,
show users a dialog prompting them to switch to 3-button navigation, The
dialog includes a deep link to the navigation mode settings.

Video: http://shortn/_ZoDV2Lwt4Z

Bug: b/413082864
Test: atest
Flag: com.android.server.accessibility.enable_autoclick_indicator
Change-Id: Iab21a66187ce1af6097223d6d34220ff65b3a8ac