getAppName returns null on iOS

[gecsbernat]

Hello!

In version 0.1.14, on iOS the plugin sometimes returns null when calling getAppName.
This is because there are no localized value on every app.
So the plugin should check if there is a localized value available and if not the plugin should fall back to the non-localized value.

I am using this plugin so I had to downgrade to 0.1.12 because of this!

See the screenshot below:

I will make a pull request to fix this. Hope you will accept it!
Thank you :)

[sampart]

Fixed by #132