Don't reset translation callback with other state

This fixes issues with Views that have their own custom
ViewTranslationCallback.

Bug: 236678324
Test: atest CtsTranslationTestCases
Test: manual - Verified on chat app that uses their own custom
ViewTranslationCallback; old and new messages are translated
Test: manual - Spot-checked translation on a few other chat apps

Change-Id: If4194bc8cde73a9cebb7b56594f6982855374410