Use CALLED_FROM_SETUP instead of KATI

So that we can use kati instead of make for the initial config loading.

Test: m clean; m nothing
Test: USE_GOMA=true m nothing
Test: m PRODUCT-aosp_x86-sdk
Test: m APP-Calculator
Test: multiproduct_kati -only-config  (on AOSP and internal master)
Change-Id: I5d3af847607fa48868c2045401977eca37dc6ae1