Make sure to not call getTelephonyManager with null context

                            // TODO: Filter out emergency numbers if

                            // the carrier does not want redial for

                            // these.

                            // If the fragment has already been detached since the last time

                            // we called queryLastOutgoingCall in onResume there is no point

                            // doing anything here.

                            if (getActivity() == null) return;

                            mLastNumberDialed = number;

                            updateDialAndDeleteButtonEnabledState();

                        }