Send the TranslationRequest which collected from the UI toolkit to
the TranslationService. And apply the result to the UI toolkit to
show the translated text.
Bug: 172969740
Bug: 177887860
Test: Verified by using a sample app and made sure the full flow work
and the text was replaced with translated text.
Change-Id: I1db4d1eabe5bc65d8785f13f760af54f74e46c97