In "Change I95ed2aae: Stop using shared DUN APN when tethering stops", sha1: 8beff9586ff89a1e59469e9820fd9e9d704300d2, an assumption is made that the msg.obj is always an ApnContext, this is not true for CDMA. Eventually we plan on removing the destinction between GSM and CDMA but for now we need to handle it handle it. Bug: 5904734 Change-Id: I86873dc7aeda5234c14a6fe1e4ec7345ee30e957