Fix ENGINE_VERSION in mozc_version_template.bzl
Fix ENGINE_VERSION in mozc_version_template.bzl

This is a follow up CL to a previous CL [1], which should have removed
NACL_DICTIONARY_VERSION, and other previous CLs [2][3], which should
have updated ENGINE_VERSION.

Note that not updating ENGINE_VERSION is not immediately problematic
because dynamic dictoinary update is not enabled in OSS Mozc.  That
said, the current ENGINE_VERSION is 24 and correcting it should still
make sense.

This CL also add a copyright header and license notice to
mozc_version_template.bzl just in case.

 [1]: 5b9c1ed79e227c8e602dbfc91f003b334ec58bf6
 [2]: c4a2d4661a91ab8534afb40bba966036046f24df
 [3]: 25f3fcf564db7f59b5b381494f0a1d2db2473463

BUG=
TEST=
REF_BUG=
REF_CL=123078429,123191246,127786726,131517988
REF_TIME=2016-08-28T01:31:07-07:00
REF_TIME_RAW=1472373067 -0700

fcitx/mozc,google/mozc,google/mozc,fcitx/mozc,google/mozc,google/mozc,fcitx/mozc,google/mozc,fcitx/mozc,fcitx/mozc