Update preference screen title.

- Add missing title to preference screen xml so that they will be used to
set the activity title when the fragment is launched.
- Also updated some incorrect preference screen titles.
- Overrides getTitle() in preference fragments that do not use the
preference screen xml.

Bug: 64564191
Test: blaze-bin/screenshots/android/i18nscreenshots/i18nscreenshots
Change-Id: Id72d5ddf18f0962bc484de8bbd847a2e55d6371e

src/com/android/settings/applications/BackgroundCheckSummary.java

@@ -16,6 +16,7 @@
 
 package com.android.settings.applications;
 
+import android.annotation.StringRes;
 import android.app.FragmentTransaction;
 import android.os.Bundle;
 import android.preference.PreferenceFrameLayout;
@@ -57,4 +58,11 @@ public class BackgroundCheckSummary extends InstrumentedPreferenceFragment {
 
         return rootView;
     }
+
+    @Override
+    @StringRes
+    protected int getTitle() {
+        return R.string.background_check_pref;
+    }
+
 }