The news objectivity would refer to the disinterestedness, factuality, nonpartisanship, and fairness. The objectivity helps the consumers of the information to identify the badness or goodness of the subject by themselves – people should not be guided by the media what is good and what is bad.
Quality of news is a bit more complicated notion. Nevertheless, there is a classical definition. Good qualitative news should inform objectively about things happening in the world and make informed decisions. As well, news needs to help to control the government on the execution of their responsibilities and foster the development of the civil society at the whole. News objectivity is one of the important parts of the quality of news.
Thus, news quality refers to news objectivity etc. and is a bigger notion.