Can't download GoogleService-Info.plist file

It happened with me also. If you close everything and follow that link it worked for me next time. You can try to do that. Below is the link of sample plist file, of course I replaced tracking id, bundle id and app id to strings from original values. Hope it helps.

Sample Google Plist file

Steps for getting configuration if your first time login to google developer account.

1. Open google developer console.
2. Login to developer console.
3. Create project with valid name.
4. Enable google analytics. 
5. Then get the configuration file.

The download link is not always immediately visible and you have to scroll up to get it, I happen to press next before downloading and I missed the opportunity to download the file.

I prefer the automatically generated file as I am lazy (aren't we all)

So, follow these steps

1. Go to https://developers.google.com/analytics/devguides/collection/ios/v3/
2. Scroll down to Get a configuration file
3. When prompted for the app name and bundle Id, just use the drop down menu and you'll find your previously created app details there.
4. Proceed to the next screen Continue to: Choose and Configure Services

5. Select your service, note that your previously selected ones will have a green arrow (Analytics in the case below)

6. Select Generate configuration file

7. You'll be given an opportunity to download the file again.

Voila!