Log IME Touches. Design document: https://docs.google.com/document/d/1e7JrjjEVvjrUxSDuPWdsdKcGziNQbW11bdCPlCdA2Wk/edit?ts=5ed57c93#heading=h.ixy3934b5ag

bug: 159343582
Test: manual test
Change-Id: I263f9810592dcd0fc05913875dd31154d041455a
2 files changed