Add require scrolling button for FingerprintEnrolling intro

The consent in the fingerprint introduction has been updated. Users are
required to read through the content. Adding a scrolling button is to
prevent directly going to next page from this page. It also makes sure
the content has to be scrolled down to the bottom of page.

Fix: 184591438
Test: visual verified
1) Prepare a device with fingerprint sensor
2) Settings > Security > Fingerprint unlock
3) Entering the enrollment flow and see if the introduction has a button
named "More" on the right-bottom side.

Change-Id: I1916293807ca9fb04f5d576cf4f6aaccbbe1ff00

src/com/android/settings/biometrics/fingerprint/FingerprintEnrollIntroduction.java

@@ -37,6 +37,7 @@ import com.android.settingslib.RestrictedLockUtilsInternal;
 import com.google.android.setupcompat.template.FooterBarMixin;
 import com.google.android.setupcompat.template.FooterButton;
 import com.google.android.setupdesign.span.LinkSpan;
+import com.google.android.setupdesign.template.RequireScrollMixin;
 
 import java.util.List;
 
@@ -69,14 +70,18 @@ public class FingerprintEnrollIntroduction extends BiometricEnrollIntroduction {
                         .build()
         );
 
-        mFooterBarMixin.setPrimaryButton(
-                new FooterButton.Builder(this)
+        final FooterButton nextButton = new FooterButton.Builder(this)
                 .setText(R.string.security_settings_fingerprint_enroll_introduction_agree)
                 .setListener(this::onNextButtonClick)
                 .setButtonType(FooterButton.ButtonType.NEXT)
                 .setTheme(R.style.SudGlifButton_Primary)
-                        .build()
-        );
+                .build();
+
+        mFooterBarMixin.setPrimaryButton(nextButton);
+        final RequireScrollMixin requireScrollMixin =
+                getLayout().getMixin(RequireScrollMixin.class);
+        requireScrollMixin.requireScrollWithButton(this, nextButton,
+                R.string.security_settings_face_enroll_introduction_more, this::onNextButtonClick);
     }
 
     int getNegativeButtonTextId() {