Added head turn option for Face Unlock.

In security settings there is an option for head turn and it shows the current
status (on/off).  Clicking on this goes to another screen that describes the
feature and allows the user to it on/off.
Since the head turn option goes to a different screen instead of using a check box,
this change also rips out the rest of the code for the old liveliness checkbox.

Change-Id: I197af51084f3e751081fa159dadd6c2c80840d1e

res/xml/security_settings_biometric_weak.xml

@@ -30,6 +30,11 @@
             android:key="biometric_weak_improve_matching"
             android:title="@string/biometric_weak_improve_matching_title"/>
 
+        <PreferenceScreen
+           android:key="biometric_weak_liveliness"
+           android:fragment="com.android.settings.BiometricWeakLiveliness"
+           android:title="@string/biometric_weak_liveliness_title"/>
+
         <CheckBoxPreference
             android:key="visiblepattern"
             android:title="@string/lockpattern_settings_enable_visible_pattern_title"/>