Remove bottom padding below wifi preference.

- show bottom padding only when top bar is using static View
- hide wifi preference when ProgressBar is used
- show bottom padding when top bar is using static View and
  wifi preference is hidden.
- rename wifi_config_padding to content_padding, as it is not
  just for wifi config but for acquiring default hight of
  @id/content
- update screen state correctly

Bug: 3502220
Change-Id: I86c89435f43d6bd016a78f7afeb5f477f63d0696
2 files changed