Merge pull request #47301 from Okabe-Junya/update-japanese-approver

[ja] Add Okabe-Junya to sig-docs-ja-owners

Author: k8s-ci-robot

OWNERS_ALIASES

@@ -127,6 +127,7 @@ aliases:
     - bells17
     - inductor
     - nasa9084
+    - Okabe-Junya
   sig-docs-ja-reviews: # PR reviews for Japanese content
     - atoato88
     - bells17