am f9ad70a4: am f9fa08e3: am 1b1a0778: am 3ccb437d: Merge "envsetup.sh: cd to toplevel in get_build_var"

* commit 'f9ad70a472bfab4d3769cb6eece06dac8de9e3bd':
  envsetup.sh: cd to toplevel in get_build_var