UserProperties 'getIs' is just 'is'

Rename the UserProperties that start with 'getIs' to just start with
'is'. Likewise, 'setIs' becomes 'set'.

Bug: 237399048
Test: atest android.multiuser.cts.UserManagerTest
Test: atest com.android.server.pm.UserManagerTest
Test: atest UserManagerServiceUserTypeTest
Test: atest UserManagerServiceUserPropertiesTest
Test: atest AppCloningHostTest
Change-Id: I87eb58160c82ac25ef0fe595e9456029a1213e6a