Update strings and layout for enterprise privacy

This CL continues the finalization of UI layout and strings for the
enterprise privacy page:
* Turn footer into a header
* Update strings
* Dynamically generate summaries for entry points in security page

Bug: 32692748
Test: m RunSettingsRoboTests

Change-Id: Ibf248ac269380fb1b919b01f88f721130060b7f9

src/com/android/settings/enterprise/DevicePolicyManagerWrapperImpl.java

@@ -31,6 +31,11 @@ public class DevicePolicyManagerWrapperImpl implements DevicePolicyManagerWrappe
         mDpm = dpm;
     }
 
+    @Override
+    public @Nullable List<ComponentName> getActiveAdminsAsUser(int userId) {
+        return mDpm.getActiveAdminsAsUser(userId);
+    }
+
     @Override
     public int getMaximumFailedPasswordsForWipe(@Nullable ComponentName admin, int userHandle) {
         return mDpm.getMaximumFailedPasswordsForWipe(admin, userHandle);