Move version checking to soong_ui

This removes versions_checked.mk that caused kati to regenerate the
ninja file 3 times for a clean out directory. Kati needs to regenerate
every time that we write a file that we also read. soong_ui doesn't have
this problem.

Bug: 35970961
Test: m clean; m -j blueprint_tools; m -j blueprint_tools; m -j blueprint_tools
Test: $OUT_DIR/versions_checked.mk no longer exists
Change-Id: I14b67dc275ea3daa77a7315c2985dc73d77fd07c
diff --git a/CleanSpec.mk b/CleanSpec.mk
index 88f9172..b955e25 100644
--- a/CleanSpec.mk
+++ b/CleanSpec.mk
@@ -417,6 +417,9 @@
 # Soong module variant change, remove obsolete intermediates
 $(call add-clean-step, rm -rf $(OUT_DIR)/soong/.intermediates)
 
+# Version checking moving to Soong
+$(call add-clean-step, rm -rf $(OUT_DIR)/versions_checked.mk)
+
 # ************************************************
 # NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST
 # ************************************************