This change also
* Honors the custom action label in EditorInfo.actionLabel.
* Invokes InputConnection.performeEditorAction if action is specifed
at EditorInfo.imeOptions or actionLabel/actionId.
* Stops using InputMethodService.sendKeyChar. Implements
sendKeyCodePoint instead.
Bug: 2498607
Bug: 5961809
Bug: 5368408
Change-Id: If4cd5eb3dacfc6b6a7ea434b0617c2438e06e42d