android: Remove three unnecessary md5sum calls.

After r256667, the list of java files for javac is written into a gyp
filelist, which gets rewritten if a java file is removed. (If a generated
java file is removed, that still doesn't cause a rebuild, but that didn't
happen before this CL either, http://crbug.com/) This allows removing the
md5sum call for javac in java_apk.gypi.

java.gypi also has additional_input_paths as input, but that's only used
for stamp files, for ordering purposes, so it's not necessary to re-run
the javac action if a stamp file disappears from additional_input_paths.

With the same reasoning, the md5sum call in 'ant package resources' is not
needed: additional_input_paths is the only non-stamp input that isn't also
on the command line. ('ant package resources' is missing some inputs, but
that's independent of this change: http://crbug.com/351928)

No behavior change.

BUG=177552
R=cjhopman@chromium.org

Review URL: https://codereview.chromium.org/198283003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256746 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256746