docs(sample): remove protobuf feature from native image sample (#665)

* docs(sample): remove protobuf feature from native image sample

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Author: mpeddada1

samples/native-image-sample/pom.xml

@@ -121,8 +121,6 @@
               <buildArgs>
                 <buildArg>--no-fallback</buildArg>
                 <buildArg>--no-server</buildArg>
-                <buildArg>--initialize-at-build-time</buildArg>
-                <buildArg>--features=com.google.cloud.nativeimage.features.ProtobufMessageFeature</buildArg>
               </buildArgs>
             </configuration>
             <executions>