Add more Wi-Fi DPP UI features.

1. Use ConstraintLayout to fix footer buttons at bottom
2. ScrollViews have all other UI components excepts footer buttons
3. Use style/SuwGlifButton for buttons
4. Fix scan fragment crash when rotating screen

Bug: 118794978
Test: manual test
Change-Id: I509b0156c4835c75da75fb7ac4c82f55a0b506a1