convert to snake case

Signed-off-by: Willem Veerman <6502426+willemveerman@users.noreply.github.com>

contrib/golang/filters/http/source/go/pkg/http/type.go

@@ -158,9 +158,9 @@ func (h *requestOrResponseHeaderMapImpl) RangeWithCopy(f func(key, value string)
 func (h *requestOrResponseHeaderMapImpl) GetAllHeaders() map[string][]string {
 	h.mutex.Lock()
 	h.initHeaders()
-	copiedHeaders := h.headers
+	copied_headers := h.headers
 	h.mutex.Unlock()
-	return copiedHeaders
+	return copied_headers
 }
 
 // api.RequestHeaderMap