Apply suggestions from code review

Co-authored-by: Chris Smowton <[email protected]>

Author: atorralba

java/ql/lib/semmle/code/java/frameworks/android/Fragment.qll

@@ -2,7 +2,7 @@
 
 import java
 
-/** An Android Fragment. */
+/** The class `android.app.Fragment`. */
 class AndroidFragment extends Class {
   AndroidFragment() { this.getASupertype*().hasQualifiedName("android.app", "Fragment") }
 }

java/ql/lib/semmle/code/java/frameworks/android/OnActivityResultSource.qll

@@ -28,10 +28,12 @@ class OnActivityResultIncomingIntent extends DataFlow::Node {
    * Intent to `onActivityResult`.
    */
   predicate isRemoteSource() {
-    exists(ImplicitStartActivityForResultConf conf, RefType startingType, DataFlow::Node sink |
-      conf.hasFlowTo(sink) and
-      startingType = sink.asExpr().(Argument).getCall().getEnclosingCallable().getDeclaringType()
+    exists(ImplicitStartActivityForResultConf conf, RefType startingType, Expr startActivityForResultArg |
+      conf.hasFlowToExpr(startActivityForResultArg) and
+      // startingType is the class enclosing the method that calls `startActivityForResult`.
+      startingType = startActivityForResultArg.getEnclosingCallable().getDeclaringType()
     |
+      // startingType itself defines an `onActivityResult` method:
       startingType = this.getEnclosingCallable().getDeclaringType()
       or
       // A fragment calls `startActivityForResult`