tweak preference name

src/main/java/org/thoughtcrime/securesms/preferences/AdvancedPreferenceFragment.java

@@ -210,7 +210,7 @@ public class AdvancedPreferenceFragment extends ListSummaryPreferenceFragment
       callsEnabled.setOnPreferenceChangeListener((preference, newValue) -> {
         if ((Boolean)newValue) {
           new AlertDialog.Builder(requireActivity())
-            .setTitle("Thanks for trying out \"Video Calls\"!")
+            .setTitle("Thanks for trying out \"Calls\"!")
             .setMessage("• You can now call contacts\n\n"
               + "• If you want to quit the experimental feature, you can disable it at \"Settings / Advanced\"")
             .setCancelable(false)

src/main/res/values/strings.xml

@@ -369,7 +369,7 @@
     <string name="file_saved_to">File saved to \"%1$s\".</string>
 
     <string name="start_call">Call</string>
-    <string name="video_calls">Video Calls</string>
+    <string name="calls">Calls</string>
     <string name="answer_call">Answer</string>
     <string name="end_call">Decline</string>
 

src/main/res/xml/preferences_advanced.xml

@@ -23,7 +23,7 @@
         <org.thoughtcrime.securesms.components.SwitchPreferenceCompat
             android:defaultValue="false"
             android:key="pref_calls_enabled"
-            android:title="@string/video_calls"/>
+            android:title="@string/calls"/>
 
         <org.thoughtcrime.securesms.components.SwitchPreferenceCompat
             android:defaultValue="false"