[Material] Fix 20051 FAB tooltip touch target (#21084)

* [FAB] Updated tooltip touch target.

* Remove "new" keyword

* [FAB] Updated tooltip touch target.

* "long press button edge"

* remove new

* remove new

* put "new" keywords back in

* Remove check for childless tooltip

* Added regression test - tooltip works on edge of FAB which has no child.

Added helper method to find the right edge of a in the tests.

* Changed "find.byType(text)" to "find.text('Add')"