Translate selectable TextViews by temporarily disabling selectable.

The text is not selectable while translated. Making translated text
selectable requires many more changes.

This was tested in Nextdoor in the feed/posts activity. When there is a
"Read more" link in the post, the link doesn't work while translated,
and doesn't behave the same way after translation is paused.

Bug: 202966891
Test: atest CtsTranslationTestCases
Test: Manually - with Nextdoor on feed and chat activities
Change-Id: I6e8f532d427d85ff22df0deb248d8416a15f4821