BurstObservatory: add option to set http method for burst check (#4835)

* feat: add options to set method for burst check.

* chore: gen proto.

* chore: change protoc-gen-go to latest.

* revert

---------

Co-authored-by: 风扇滑翔翼 <Fangliding.fshxy@outlook.com>

app/observatory/burst/config.proto

@@ -26,4 +26,7 @@ message HealthPingConfig {
   int32 samplingCount = 4;
   // ping timeout, int64 values of time.Duration
   int64 timeout = 5;
+  // http method to make request
+  string httpMethod = 6;
+
 }