With ag/899084 TextView no longer automatically sets the
LinkMovementMethod when setText is called with a ClickableSpan.
So in LinkTextView we do that manually instead.
Bug: 27973982
Change-Id: I86626bd71bf2ca41cb7e73d479ba764e809b0190
Copied ExploreByTouchHelper, LinkAccessibilityHelper and LinkTextView
from setup wizard and switched fingerprint_settings_footer to use
LinkTextView, so that users can navigate to the link in TalkBack
mode.
Bug: 24343933
Change-Id: I0ff0c054510dfef4263ea223cb0044a4bddf321f