Remove the deprecated APIs in UiTranslationManager.

We introduced some APIs for initial demo but we dropped these APIs.
To avoid to break the client app, we keep the API until the client
moves to new APIs. It's ok to delete these API now.

Bug: 185448758
Test: manual
Test: atest android.translation.cts.UiTranslationManagerTest

Change-Id: I5ea71d4658246f52610e1f62412d60c6c58bb31e