Fix OOBE crash/DoS after receiving 0-byte WAP push.

Add a try/catch block around the code in WapPushOverSms.dispatchWapPdu(),
so we don't get into a reboot trap on receiving weirdly formed messages.
Only catch ArrayIndexOutOfBoundsException, which is difficult to
prevent inside dispatchWapPdu() for 0-byte PDUs or other unusual
contents. The caller should probably catch any unhandled exceptions of other types and log them with stack traces.

Bug: 11967705
Change-Id: Iabfec68d2564dd438d45c80cdba877bf19fa0397