Add logging enum value for long press home setting page

Adds an enum for setting page configuring long press home for 2-/3-button navigation modes.

Bug: 191888710
Test: Trivial
Change-Id: I9e0636ab716d1a9dde120c9c936efbd64a8a8b0a
Merged-In: I9e0636ab716d1a9dde120c9c936efbd64a8a8b0a