title: Cannot resolve AppCompatActivity after upgrade project from gradle 2.1 to 3.5
body: <p>I successfully upgrade gradle from 2.10 to 3.5 to build APK in android studio 3, but have problem like this
  <a href="https://i.stack.imgur.com/jKKL3.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/jKKL3.png" alt="Cannot Resolve AppCompatActiviy"></a></p>
  
  <p>And this is my build gradle <a href="https://i.stack.imgur.com/rae7O.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/rae7O.png" alt="Build Gradle"></a></p>