bug[ats_ATS141237]: Handle Null Pointer in ArtifactSearch_V1.search

Change-Id: I020f9c88eafb4d078bcf5a633e4d18b4c8d9347b
bug[ats_ATS141237]: Add null condition check to client search

Change-Id: I986abd17f3d086880be7a8a2f0dbbd0dab0140b6