[TIMOB-15904] iOS: Push Notification - On 6.X devices, you will not receive a background push notification with NEW iOS push certs on first install

*Details:* If you build an app with *new* iOS push certs, you will not receive a background push on 6.X iOS devices on first install. However, if you reinstall the app on the same 6.X device, then you will be able to receive a background push notification. *Note:* 1. This is *not* a regression. Still occurs with GA stack. 2. This is not reproducible on a 7.X iOS device. 3. On a 6.X iOS device, push notification can still be sent if the app is in the *foreground.* *Steps to reproduce:* 1. Create new iOS push certs with a different app id: https://wiki.appcelerator.org/display/qe/How+to+generate+a+iOS+push+cert 2. Next, create a Titanium classic app with ACS enabled 3. Copy the ti.cloud sample app (~/Library/Application Support/Titanium/modules/commonjs/ti.cloud/3.2.0/example/*) into the Titanium app Resources directory 4. Install app to a 6.X device 5. Next, go to the ACS dashboard: cloud.appcelerator.com/apps/ 6. Create an ACS user and upload your iOS push .p12 file 7. Next, launch the ACS app and login using the newly created ACS user 8. Go to Push Notifications > Settings for This Device and press Disabled to Enable push 9. Go to Push Notifications > Subscribe and subscribe to a channel 10. Background the app 11. On the ACS dashboard, send a push notification with an Alert, Badge, and Sound (default) *Actual:* A push notification is not received when the app is in the background. And, app does not appear in the notification setting (see no_app.png) *Expected:* A push notification should be received when the app is in the background for a 6.X iOS device. *Workaround:* Uninstall the app and install the same app back onto device. App will appear in the notification setting (see there_is_app.png) and you will be able to send a push notification while the app is in the background.