Adds search_all_entrypoints_enabled setting.

This replaces 2 previous settings for long press home and navbar.

For the most part, I deleted the old versions, but I left the
ones in secure.proto feeling that the numbers might get reused by
accident.

Bug: 324036308
Test: Manual and unit tests
Flag: NA
Change-Id: Ia91d82f51931ca5370786a37f18f9e6dafab3f71
Merged-In: Ia91d82f51931ca5370786a37f18f9e6dafab3f71