[UIComponentContext] Added UIContext to mutable_local_variables whitelist

Summary:
We want to allow following declaration

```
CK::UIContext t(foo);
```

In this case t is only part of the scope and we don't want to check that is never mutated.

Reviewed By: kfirapps

Differential Revision: D17367040

fbshipit-source-id: 5312a1249

infer/src/al/ComponentKit.ml

@@ -108,7 +108,8 @@ let mutable_local_vars_advice context an =
         ; "FBTrackingNodeScope"
         ; "FBTrackingCodeScope"
         ; "CKComponentContext"
-        ; "CKComponentKey" ]
+        ; "CKComponentKey"
+        ; "UIContext" ]
       in
       let objc_whitelist = ["NSError"] in
       match get_referenced_type qual_type with