fix(tests): Fix dumpView test util for changed modules API.

Author: hdeshev

tests/app/tests/test-utils.ts

@@ -4,7 +4,7 @@ import {Device} from "platform";
 
 function getChildren(view: View): Array<View> {
     var children: Array<View> = [];
-    (<any>view)._eachChildView((child) => {
+    (<any>view).eachChildView((child) => {
         children.push(child);
         return true;
     });
@@ -41,4 +41,4 @@ export function createDevice(os: string): Device {
         manufacturer: "tester",
         model: "test device"
     };
-}
+}