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