[Xamarin.GoogleAndroid.Libraries.Places] Exclude the OkHttp dependency (#1246)

It is not needed as the underlying library
uses `grpc-okhttp` instead. This is a fork
and modification of the `OkHttp` library
and the code says it is 2.5.0+

https://github.com/grpc/grpc-java/blob/f50726d32e216746642513add28e086094ce5506/okhttp/third_party/okhttp/main/java/io/grpc/okhttp/internal/Platform.java#L18

Author: mattleibow

config.json

@@ -3174,8 +3174,9 @@
         "groupId": "com.google.android.libraries.places",
         "artifactId": "places",
         "version": "4.4.1",
-        "nugetVersion": "4.4.1",
+        "nugetVersion": "4.4.1.1",
         "nugetId": "Xamarin.GoogleAndroid.Libraries.Places",
+        "excludedRuntimeDependencies": "com.squareup.okhttp.okhttp",
         "type": "xbd"
       },
       {