Fix Hackbook graph api usage

Summary:
Hackbook adopts the migration bundle of the SDK in general, meaning it gets updated profile picture viewer semantics, and thus receives an array rather than just a URL.

Modify the accessor to dive in and get the URL when the 'details' isn't a string.

Test Plan: Ran Hackbook

Reviewers: jacl, chrisp, clang, mmarucheck, ayden, karthiks, mingfli, caabernathy

Reviewed By: jacl

CC: msdkexp@

Differential Revision: https://phabricator.fb.com/D582510

samples/Hackbook/Hackbook/APIResultsViewController.m

@@ -249,7 +249,14 @@ - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(N
     cell.textLabel.numberOfLines = 2;
     // If extra information available then display this.
     if ([[myData objectAtIndex:indexPath.row] objectForKey:@"details"]) {
-        cell.detailTextLabel.text = [[myData objectAtIndex:indexPath.row] objectForKey:@"details"];
+
+        id details = [[myData objectAtIndex:indexPath.row] objectForKey:@"details"];
+        if (![details isKindOfClass:[NSString class]]) {
+            // If details isn't a string, it's the return data for an image request, and we pull
+            // the url for it.
+            details = [[details objectForKey:@"data"] objectForKey:@"url"];
+        }
+        cell.detailTextLabel.text = details;
         cell.detailTextLabel.font = [UIFont fontWithName:@"Helvetica" size:12.0];
         cell.detailTextLabel.lineBreakMode = UILineBreakModeCharacterWrap;
         cell.detailTextLabel.numberOfLines = 2;