Creates a dummy pointer for empty messages

Changes to Java HIDL at ContextHubService caused empty messages with
sendMessageToHub to be populated with null pointers. Work around this by
creating a dummy pointer in this case.

Bug: 69065562
Test: Compile on sailfish-userdebug, run CHQTS and verify pass
Change-Id: I763cbf9696f6dc04637add3ed1da01f9c32d458b
1 file changed