Merge remote-tracking branch 'aosp/upstream' into master

* aosp/upstream:
  Make test_tree_tests.sh slightly easier to read
  No longer follow subdirs in Android.bp files
  Support for a custom list of Blueprints files to parse
  Make a copy of Blueprint in tests
  Move parseOne for readability
  Clarify context.go somewhat

Test: m -j checkbuild
Change-Id: I703fe344bff4660bea6ca99b74a1dff86cf11feb