Add ktlint to preupload hooks

The kotlin linter is particularly useful for tests written in Kotlin in
frameworks/base.

This is already merged in internal master.

Test: Tried uploading change with/without kotlin style problems.
Merged-In: Ie8659765b674ac7b2d82ed3d343f387195c07d83
Change-Id: I420366c49d071e022b8988c3d6293dbc8e9a283a