android: Remove unused codegen_input_paths and library_manifest_paths.

As far as I can tell, nothing ever sets them. Remove them and the ant code
that runs only when library_manifest_paths is set. No intended behavior change.

BUG=177552
R=cjhopman@chromium.org

Review URL: https://codereview.chromium.org/177923012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255971 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 255971