Add Fragment.onViewCreated as a known initializer. (#279)

From the documentation:

"Called immediately after onCreateView(LayoutInflater, ViewGroup, Bundle) has returned, but before any saved state has been restored in to the view."

So, if one is an initializer, the other should be as well.

nullaway/src/main/java/com/uber/nullaway/ErrorProneCLIFlagsConfig.java

@@ -75,18 +75,21 @@ final class ErrorProneCLIFlagsConfig extends AbstractConfig {
           "android.app.Fragment.onCreate",
           "android.app.Fragment.onAttach",
           "android.app.Fragment.onCreateView",
+          "android.app.Fragment.onViewCreated",
           "android.app.Application.onCreate",
           "javax.annotation.processing.Processor.init",
           // Support Library v4 - can be removed once AndroidX becomes more popular
           "android.support.v4.app.ActivityCompat.onCreate",
           "android.support.v4.app.Fragment.onCreate",
           "android.support.v4.app.Fragment.onAttach",
           "android.support.v4.app.Fragment.onCreateView",
+          "android.support.v4.app.Fragment.onViewCreated",
           // Support Library v4 - can be removed once AndroidX becomes more popular
           "androidx.core.app.ActivityCompat.onCreate",
           "androidx.fragment.app.Fragment.onCreate",
           "androidx.fragment.app.Fragment.onAttach",
           "androidx.fragment.app.Fragment.onCreateView",
+          "androidx.fragment.app.Fragment.onViewCreated",
           // Multidex app
           "android.support.multidex.Application.onCreate");