Dialer: Fix proto warning with optmize for lite

* option optimize_for = LITE_RUNTIME is ignored in proto 3+
* Instead we should use the java_lite compiler via the
  LOCAL_PROTOC_OPTIMIZE_TYPE flag which defaults to lite in
  java projects

Test: m Dialer, no warnings
Change-Id: I552f5895bbe8192a4ae870bb48e5ef6a9e7e8c78