2/n: Add default implementation for multi-biometric enroll

1) Adds a layout for multi-biometric selection in BiometricEnrollActivity
2) Adds widgets for checkboxes
3) Shows ConfirmLock*/ChooseLock* for multi-biometric devices in
   BiometricEnrollActivity
4) finish()'s when loses foreground
5) Adds default string for ChooseLock* and multi-biometrics, e.g.
   "Set up Password + Biometrics", as well as associated plumbing
   to bring the user back to BiometricEnrollActivity once the
   credential is enrolled
6) When max templates enrolled, checkbox becomes disabled and
   description string is updated

Bug: 162341940
Bug: 152242790
Fixes: 161742393

No effect on existing devices with the following:
Test: adb shell am start -a android.settings.BIOMETRIC_ENROLL
Test: SUW
Test: make -j RunSettingsRoboTests

Exempt-From-Owner-Approval: Biometric-related change
to EncryptionInterstitial

Change-Id: I855460d50228ace24d4ec5fbe330f02ab406cc02

tests/robotests/src/com/android/settings/testutils/shadow/ShadowFingerprintManager.java

@@ -18,22 +18,30 @@ package com.android.settings.testutils.shadow;
 
 import android.hardware.fingerprint.Fingerprint;
 import android.hardware.fingerprint.FingerprintManager;
+import android.hardware.fingerprint.FingerprintSensorProperties;
 
 import org.robolectric.annotation.Implementation;
 import org.robolectric.annotation.Implements;
 
+import java.util.ArrayList;
 import java.util.List;
 
 @Implements(FingerprintManager.class)
 public class ShadowFingerprintManager extends org.robolectric.shadows.ShadowFingerprintManager {
 
+    private static List<FingerprintSensorProperties> sFingerprintSensorProperties;
+
+    public static void setSensorProperties(List<FingerprintSensorProperties> props) {
+        sFingerprintSensorProperties = props;
+    }
+
     @Implementation
     protected List<Fingerprint> getEnrolledFingerprints(int userId) {
         return getEnrolledFingerprints();
     }
 
     @Implementation
-    protected long generateChallengeBlocking() {
-        return 0L;
+    protected List<FingerprintSensorProperties> getSensorProperties() {
+        return sFingerprintSensorProperties;
     }
 }