Don't index the ChooseLockGeneric screen

This avoids indexing face unlock, which may not always exist or might
be disabled by policy.

Instead, add some of the relevant keywords up one level in Security
settings.

Bug: 17185326
Change-Id: I4fbae1c0384a97383707104a6fe283075edbf341
diff --git a/res/xml/security_settings_pattern.xml b/res/xml/security_settings_pattern.xml
index cb848c6..ceb749c 100644
--- a/res/xml/security_settings_pattern.xml
+++ b/res/xml/security_settings_pattern.xml
@@ -15,6 +15,7 @@
 -->
 
 <PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
+                  xmlns:settings="http://schemas.android.com/apk/res/com.android.settings"
                   android:title="@string/lock_settings_picker_title">
 
     <PreferenceCategory
@@ -25,6 +26,7 @@
             android:key="unlock_set_or_change"
             android:title="@string/unlock_set_unlock_launch_picker_title"
             android:summary="@string/unlock_set_unlock_mode_pattern"
+            settings:keywords="@string/keywords_lockscreen"
             android:persistent="false"/>
 
         <SwitchPreference