style(springboot autoconfigure): use a PROPERTY_PREFIX instead of hardcoded prefix(#1225)

create a public static final value PROPERTY_PREFIX in DaprClientProperties
change the prefix value in the ConfigurationProperties to DaprClientProperties.PROPERTY_PREFIX
Dapr Cloud Config rely on that.

Signed-off-by: lony2003 <[email protected]>

Author: lony2003

dapr-spring/dapr-spring-boot-autoconfigure/src/main/java/io/dapr/spring/boot/autoconfigure/client/DaprClientProperties.java

@@ -16,8 +16,10 @@
 import io.dapr.spring.data.DaprKeyValueAdapterResolver;
 import org.springframework.boot.context.properties.ConfigurationProperties;
 
-@ConfigurationProperties(prefix = "dapr.client")
+@ConfigurationProperties(prefix = DaprClientProperties.PROPERTY_PREFIX)
 public class DaprClientProperties {
+  public static final String PROPERTY_PREFIX = "dapr.client";
+
   private String httpEndpoint;
   private String grpcEndpoint;
   private Integer httpPort;