Fixing issue where memory would bloat in UITest runner when running o…

…n device. It seemed to have been caused by XCUIApplication() getting called multiple times per execution of an action. Its now only retained once per action.

SwiftMonkey/Monkey.swift

@@ -217,23 +217,24 @@ public class Monkey {
      and not in some other app that the Monkey randomly opened.
      */
     func actInForeground(_ action: @escaping ActionClosure) -> ActionClosure {
-        return {
-            guard #available(iOS 9.0, *) else {
-                action()
-                return
-            }
-            let closure: ActionClosure = {
-                if XCUIApplication().state != .runningForeground {
-                    XCUIApplication().activate()
-                }
-                action()
-            }
-            if Thread.isMainThread {
-                closure()
-            } else {
-                DispatchQueue.main.async(execute: closure)
-            }
-        }
+		guard #available(iOS 9.0, *) else {
+			return action
+		}
+
+		let app = XCUIApplication()
+		let closure: ActionClosure = {
+			if app.state != .runningForeground {
+				app.activate()
+			}
+			action()
+		}
+		return {
+			if Thread.isMainThread {
+				closure()
+			} else {
+				DispatchQueue.main.async(execute: closure)
+			}
+		}
     }
 
     /**