Port Moterm to Mozart.

Much of the glue code has been eliminated by use of the new UI helpers.

BUG=
R=abarth@google.com, viettrungluu@chromium.org

Review URL: https://codereview.chromium.org/1556683004 .
diff --git a/apps/BUILD.gn b/apps/BUILD.gn
index 4765a5f..7f482c9 100644
--- a/apps/BUILD.gn
+++ b/apps/BUILD.gn
@@ -18,6 +18,8 @@
     ":portable_apps",
     "//apps/benchmark",
     "//apps/benchmark:apptests",
+    "//apps/moterm",
+    "//apps/moterm:apptests",
   ]
 
   if (is_android) {