Update build.gradle

build.gradle

@@ -20,6 +20,8 @@ dependencies {
 
     // https://mvnrepository.com/artifact/io.grpc/grpc-all
     compile group: 'io.grpc', name: 'grpc-all', version: '1.25.0'
+    
+    compile 'com.google.code.gson:gson:2.8.6'
 }