[buteo-sync-plugins] Make Bluetooth synced contacts modifiable

This commit ensures that contacts synced from Bluetooth devices
are marked as modifiable on the local device, as it is assumed
that the data is all owned by the user rather than a remote
service.

storageplugins/hcontacts/ContactsBackend.cpp

@@ -417,6 +417,10 @@ void ContactsBackend::prepareContactSave(QList<QContact> *contactList)
                 originMetaData.setId(iOriginId);
                 contact->saveDetail(&originMetaData);
             }
+            Q_FOREACH (QContactDetail det, contact->details()) {
+                det.setValue(QContactDetail__FieldModifiable, true);
+                contact->saveDetail(&det);
+            }
         }
     }
 }