Add summary text to Lock screen preferences.

Each time we refresh the security preference page, get the current
summary text from "On the lock screen" and populate to Lock screen
preferences summary.

Bug: 36540633
Test: make RunSettingsRoboTests
Change-Id: I317e3892b35b30981b62f7b7aee9cfdacd04a3ed

res/values/strings.xml

@@ -750,8 +750,6 @@
     <string name="encryption_and_credential_settings_summary">Phone encrypted</string>
     <!-- Security Settings screen setting option title for the item to take you to the lock screen preference screen [CHAR LIMIT=60] -->
     <string name="lockscreen_settings_title">Lock screen preferences</string>
-    <!-- Security Settings screen setting option summary for the item to take you to the lock screen preference screen -->
-    <string name="lockscreen_settings_summary">Show all notification content</string>
 
     <!-- Main Settings screen setting option summary text for the item tot ake you to the security and location screen -->
     <string name="security_settings_summary">Set My Location, screen unlock, SIM card lock, credential storage lock</string>

res/xml/security_settings_chooser.xml

@@ -31,7 +31,6 @@
 
         <Preference android:key="lockscreen_preferences"
             android:title="@string/lockscreen_settings_title"
-            android:summary="@string/lockscreen_settings_summary"
             android:fragment="com.android.settings.security.LockscreenDashboardFragment"/>
 
     </PreferenceCategory>

res/xml/security_settings_password.xml

@@ -30,7 +30,6 @@
 
         <Preference android:key="lockscreen_preferences"
             android:title="@string/lockscreen_settings_title"
-            android:summary="@string/lockscreen_settings_summary"
             android:fragment="com.android.settings.security.LockscreenDashboardFragment"/>
 
     </PreferenceCategory>

res/xml/security_settings_pattern.xml

@@ -30,7 +30,6 @@
 
         <Preference android:key="lockscreen_preferences"
             android:title="@string/lockscreen_settings_title"
-            android:summary="@string/lockscreen_settings_summary"
             android:fragment="com.android.settings.security.LockscreenDashboardFragment"/>
 
     </PreferenceCategory>

res/xml/security_settings_pin.xml

@@ -30,7 +30,6 @@
 
         <Preference android:key="lockscreen_preferences"
             android:title="@string/lockscreen_settings_title"
-            android:summary="@string/lockscreen_settings_summary"
             android:fragment="com.android.settings.security.LockscreenDashboardFragment"/>
 
     </PreferenceCategory>