cloud drive: add support for Baidu BOS

other/java/client/src/main/proto/filer.proto

@@ -408,11 +408,17 @@ message RemoteConf {
     string aliyun_access_key = 25;
     string aliyun_secret_key = 26;
     string aliyun_endpoint = 27;
+    string aliyun_region = 28;
 
     string tencent_secret_id = 30;
     string tencent_secret_key = 31;
     string tencent_endpoint = 32;
 
+    string baidu_access_key = 35;
+    string baidu_secret_key = 36;
+    string baidu_endpoint = 37;
+    string baidu_region = 38;
+
 }
 
 message RemoteStorageMapping {