Add new UserProperty ShowInSettings

Indicates whether apps in the given user profile should be displayed
with either parent, separately or not at all.

Bug: 235065648
Test: atest UserManagerServiceUserPropertiesTest
Test: atest android.multiuser.cts.UserManagerTest
Test: atest com.android.server.pm.UserManagerTest
Change-Id: I17e127cab37c11f806b535ab29762dd2a99716a5