gradle: also inject mkdir when modifying gradlew

Now that there are no committed files in the gradle/wrapper subdirectory,
it isn't guaranteed to exist, and if it doesn't, curl fails.

Change-Id: Id577d4f74c408723ac18cbfbdaca12f9affca483
Reviewed-on: http://gerrit.cloudera.org:8080/7939
Reviewed-by: Grant Henke <granthenke@gmail.com>
Reviewed-by: Dan Burkert <danburkert@apache.org>
Tested-by: Kudu Jenkins
(cherry picked from commit c8ad6668e8ebe17ff12c70cc77a8ed351595d1e3)
Reviewed-on: http://gerrit.cloudera.org:8080/7940
Reviewed-by: Adar Dembo <adar@cloudera.com>
2 files changed