Upgrade Cloud Firestore dependency (#331)

Will provide IN query features

Author: achuinard

pom.xml

@@ -422,7 +422,7 @@
         <dependency>
             <groupId>com.google.cloud</groupId>
             <artifactId>google-cloud-firestore</artifactId>
-            <version>1.21.0</version>
+            <version>1.31.0</version>
         </dependency>
 
         <!-- Utilities -->