Fix format

Author: Quinn-With-Two-Ns

temporal-sdk/src/main/java/io/temporal/internal/worker/AsyncWorkflowPollTask.java

@@ -2,7 +2,6 @@
 
 import static io.temporal.serviceclient.MetricsTag.METRICS_TAGS_CALL_OPTIONS_KEY;
 
-import com.google.protobuf.Timestamp;
 import com.uber.m3.tally.Scope;
 import com.uber.m3.util.ImmutableMap;
 import io.grpc.Context;