<fix>[host]: Support recognition for helix OS

Support identify helix OS on the web ui.

Resolves: ZSTAC-56022

Change-Id: I6d796b7467787371616d776f786c71776d617a65

Author: littleya

kvmagent/kvmagent/plugins/host_plugin.py

@@ -999,6 +999,8 @@ def _cache_units_convert(self, str):
     def fact(self, req):
         rsp = HostFactResponse()
         rsp.osDistribution, rsp.osVersion, rsp.osRelease = platform.dist()
+        if rsp.osDistribution == 'centos':
+            rsp.osDistribution = platform.linux_distribution()[0].lower()
         rsp.osRelease = rsp.osRelease if rsp.osRelease else "Core"
         # compatible with Kylin SP2 HostOS ISO and standardized ISO
         rsp.osRelease = rsp.osRelease.replace('ZStack', 'Sword') if rsp.osDistribution == "kylin" else rsp.osRelease