You shouldn't flag questions just because you think they're easy to answer by searching the web. Flagging is for exceptional cases that really need moderator intervention or at least speedy action by trusted members of the site.
If you don't like a question you can downvote. The description of downvoting already caters for that exact case ("does not show any research effort").
Also, what may seem obvious to you from a web search may not be so clear to someone else. Often answering is just about rephrasing information found elsewhere to target it directly at the specific details of the question asked, or going into more detail, or explaining it better.
So it'll probably be treated as "not constructive" if you just say "use google".
In fact one of the explicit goals of StackExchange is to improve the quality of the information that can be found by searching the web.