Use Bundle for inter-process message

The message sent from NetworkScanRequestTracker to TelephonyScanManager
might be across different process, so we have to wrap the List<CellInfo> into
Bundle because List<> is not parcelable.

Test: Telephony sanity tests
Bug: 30954762
Change-Id: I77945b247530b85c0b82876d528549498a711550