Assert getService does not return nullptr

Make sure getService return value is not null before running
testcase

Test: make vts -j40 && vts-tradefed run commandAndExit vts -m
VtsHalConfigstoreV1_0Target
Bug:62931371

Change-Id: I432e07c0c61a308b814d88cab9027a95ff24d8b5
1 file changed