Fix up ConfiguredValueTaskAwaitable signature for new compiler checks (#15092)

Signed-off-by: dotnet-bot-corefx-mirror <dotnet-bot@microsoft.com>

Author: jkotas

src/Common/src/CoreLib/System/Runtime/CompilerServices/ConfiguredValueTaskAwaitable.cs

@@ -74,7 +74,7 @@ public void UnsafeOnCompleted(Action continuation) =>
 
             /// <summary>Gets the task underlying the incomplete <see cref="_value"/>.</summary>
             /// <remarks>This method is used when awaiting and IsCompleted returned false; thus we expect the value task to be wrapping a non-null task.</remarks>
-            (Task, bool) IConfiguredValueTaskAwaiter.GetTask() => (_value.AsTaskExpectNonNull(), _continueOnCapturedContext);
+            (Task task, bool continueOnCapturedContext) IConfiguredValueTaskAwaiter.GetTask() => (_value.AsTaskExpectNonNull(), _continueOnCapturedContext);
         }
     }