Show "Labels" header when group menus are available

Bug: 35048258

Test: Manually verified "Labels" header shows up when either group
      writable account is available or group menus are available.

Change-Id: I7aeb05ed61fa84123fa5c93da111e0526946b1e2
diff --git a/src/com/android/contacts/drawer/DrawerAdapter.java b/src/com/android/contacts/drawer/DrawerAdapter.java
index 5248603..54cd669 100644
--- a/src/com/android/contacts/drawer/DrawerAdapter.java
+++ b/src/com/android/contacts/drawer/DrawerAdapter.java
@@ -130,7 +130,7 @@
         mItemsList.add(mStatusBarSpacerItem);
         mItemsList.add(mNavSpacerItem);
         mItemsList.addAll(mPrimaryItems);
-        if (mAreGroupWritableAccountsAvailable) {
+        if (mAreGroupWritableAccountsAvailable || !mGroupEntries.isEmpty()) {
             mItemsList.add(mGroupHeader);
         }
         mItemsList.addAll(mGroupEntries);