Issue with Google analytics in Xamarin forms

I am implementing Google Analytics in Xamarin forms, I followed https://theconfuzedsourcecode.wordpress.com/2015/07/19/google-analytics-tracking-implementation-in-xamarin/ . As article says to add reference to Google Play service Analytics, I did same thing but after adding reference it started giveing error for Android SDK files. I got errors like
1. Error 7 Please install package: 'GPS Ads' available in SDK installer. Android resource directory /%LocalAppData%/Xamarin\GooglePlayServices.Ads\8.1.0\embedded./ doesn't exist.

2.Error 13 Please install package: 'GPS Analytics' available in SDK installer. Android resource directory %LocalAppData%\Xamarin\GooglePlayServices.Analytics\8.1.0\embedded./ doesn't exist.
3. same as above for GPS AppIndexing
4. same as above for GPS Basement

5.Error 3 Reason: %LocalAppData%\Xamarin\zips\E86F22CB8149017F0367E79D403F0139.zip is not a valid zip file GA3.Droid
Total 8 times

1. Error 2 Unzipping failed. Please download https://dl-ssl.google.com/android/repository/google_m2repository_r22.zip and extract it to the C:\Users\amolh\AppData\Local\Xamarin\GooglePlayServices.Ads\8.1.0\content directory. GA3.Droid
   Total 8 times for 1. Ads 2.Analytics 3. AppIndexing 4. Basement

I saw at file system
1. %LocalAppData% \Xamarin\GooglePlayServices.Ads\8.1.0 is empty.
2. E86F22CB8149017F0367E79D403F0139 zip is present but it can't be unzipped, not even manually.

Thanks in advance,