Implement Wi-Fi DPP UI.

  Add WifiDppEnrolleeActivity
  Remove bottom buttons of WifiDppQrCodeScannerFragment
  Add ActionBar in WifiDppQrCodeScannerFragment &
      WifiDppQrCodeGeneratorFragment

Bug: 118797380
Bug: 118794858
Test: atest WifiDppConfiguratorActivityTest
      atest WifiDppQrCodeScannerFragmentTest
      atest WifiDppQrCodeGeneratorFragmentTest
      atest atest RunSettingsRoboTests

Change-Id: I1d464dc9a8d54a896b8e0c9185a74bed7b193b60