Merge pull request #1498 from k8s-infra-cherrypick-robot/cherry-pick-1493-to-release-1.12

[release-1.12] add songjiaxun to owners

Author: k8s-ci-robot

OWNERS

@@ -7,6 +7,7 @@ reviewers:
   - sunnylovestiramisu
   - pwschuurman
   - tyuchn
+  - songjiaxun
 approvers:
   - amacaskill
   - leiyiz
@@ -16,6 +17,7 @@ approvers:
   - sunnylovestiramisu
   - pwschuurman
   - tyuchn
+  - songjiaxun
 emeritus_reviewers:
   - davidz627
   - jingxu97