use plus icon/primary for new group conversation

Signed-off-by: Andy Scherzinger <info@andy-scherzinger.de>

app/src/main/java/com/nextcloud/talk/controllers/ContactsController.java

@@ -672,7 +672,7 @@ public class ContactsController extends BaseController implements SearchView.OnQ
 
         publicCallLinkImageView
                 .getBackground()
-                .setColorFilter(ResourcesCompat.getColor(getResources(), R.color.colorBackgroundDarker, null),
+                .setColorFilter(ResourcesCompat.getColor(getResources(), R.color.colorPrimary, null),
                                 PorterDuff.Mode.SRC_IN);
 
         disengageProgressBar();

app/src/main/res/layout/conversation_privacy_toggle.xml

@@ -46,7 +46,7 @@
             android:background="@drawable/round_bgnd"
             android:contentDescription="@null"
             android:padding="@dimen/standard_half_padding"
-            android:src="@drawable/ic_contacts"
+            android:src="@drawable/ic_add_white_24px"
             app:tint="@color/white" />
 
         <TextView