deps: Convert from JacksonFactory to GsonFactory (#780)

Author: Capstan

datastore-v1-proto-client/pom.xml

@@ -50,7 +50,7 @@
 
  <dependency>
  <groupId>com.google.http-client</groupId>
- <artifactId>google-http-client-jackson2</artifactId>
+ <artifactId>google-http-client-gson</artifactId>
  </dependency>
 
  <dependency>

datastore-v1-proto-client/src/main/java/com/google/datastore/v1/client/DatastoreHelper.java

@@ -22,7 +22,7 @@
 import com.google.api.client.http.HttpRequest;
 import com.google.api.client.http.HttpTransport;
 import com.google.api.client.json.JsonFactory;
-import com.google.api.client.json.jackson2.JacksonFactory;
+import com.google.api.client.json.gson.GsonFactory;
 import com.google.datastore.v1.ArrayValue;
 import com.google.datastore.v1.CompositeFilter;
 import com.google.datastore.v1.Entity;
@@ -138,7 +138,7 @@ private static HttpTransport newTransport() throws GeneralSecurityException, IOE
  }
 
  static JsonFactory newJsonFactory() {
- return new JacksonFactory();
+ return new GsonFactory();
  }
 
  /**