Revert ag/22361082 and ag/22460413, show the split screen dialog on
the introduction and enrolling page, instead of relying on the callers
to show the dialog.
Test: atest BiometricsSplitScreenDialogTest
Test: atest FaceEnrollIntroductionTest
Test: atest SetupFingerprintEnrollIntroductionTest
Bug: 299573056
Change-Id: Ieb106a4a623ad5ca0e6eb1633413df75767bef52
Test: atest CombinedBiometricProfileSettingsTest
Test: atest FingerprintSettingsFragmentTest
Test: manaul test- go to split screen mode and try to enroll
face
Bug: 276938441
Change-Id: I45e859b453700aa79f7774fb5deda81b1f30e5a5