Jack Yu f00ff3c93b Added nullable callback support ...

Sometimes data service clients do not care the result of the
requests so they pass null callback. In this case the data service
should handle it.

Test: Manual
Bug: 64132030
Change-Id: Ib188994fed4e708de875a24d5386a74a8f6db4dd

2018-01-27 01:28:21 +00:00

..

telephony

Added nullable callback support

2018-01-27 01:28:21 +00:00