(2/2)Refine the requireScrollMixin usage for footer buttons

- Use the 2 buttons APIs by SUW design lib suggestion
- Do not handle the FooterButton visibility when
  isExpressiveStyle is true
- Do not handle the FooterButton visibility when
  isExpressiveStyle is true
- Deprecate static BiometricUtils.isExpressiveStyle(context, false)
  original logic always assume the UI will be used in SUW
- Deprecate static BiometricUtils.useExpressiveStyle(context, intent)
  Always rely on ThemeHelper.shouldApplyGlifExpressiveStyle(context)

Flag: N/A EXEMPT for the bug fixing
Bug: 412572626
Bug: 418694831
Bug: 418679772
Bug: 418643097
Bug: 418637456
Bug: 419178138

Test: atest FaceEnrollIntroductionTest
Test: manual check both SUW & Settings UI visual meet expressive
Test: manual tap "More" and show "I agree"
      Swipe back from Edu page and make sure the buttons
      showing correctly
Test: Folded & Unfolded, orientation changed and the buttons
      works as expected
Change-Id: Ia17da47461363c54f61c29a77589288f880100a6