httpdns 缓存策略，特殊接口获取 httpdns 服务

foudations/httpdns-base/src/main/java/com/mogo/httpdns/IHttpDnsCallback.java

@@ -0,0 +1,18 @@
+package com.mogo.httpdns;
+
+import androidx.annotation.Keep;
+import androidx.annotation.Nullable;
+
+public
+/**
+ * @author congtaowang
+ * @since 2020/11/19
+ *
+ * dns 解析回调
+ */
+@Keep
+interface IHttpDnsCallback {
+
+    @Keep
+    void onParsed( @Nullable String ip );
+}