Replace calls to FileUtils.touch with calls to similar methods.

FileUtils.touch is changing behavior, including:

- not creating parent directories when necessary
- failing when the file is a symlink to a non-existent file, or
  something like that?

This change was proposed as a Google-internal CL and this change is
applying it in the open source project.

Change-Id: I495072fca9f48349e4391cf905935fa82729f752
Signed-off-by: Edwin Kempin <ekempin@google.com>