wear_ui: Remove dead/duplicate codes.

WearRecoveryUI::draw_progress_locked() has declaration only, where
the definition was deleted in commit
5e7cfb9a.

WearRecoveryUI::ClearText() is a duplicates of
ScreenRecoveryUI::ClearText().

Test: Build swordfish recovery image. 'Run graphics test' and 'View
      recovery logs'.
Change-Id: Ib66955d1d496f04359b4d6487160218e8f954478