[web] update time period string on group plans (#23465)

GitOrigin-RevId: b62991ffe122cae877c0d05b71d29619e25684d9

services/web/locales/en.json

@@ -1531,8 +1531,7 @@
   "per_month": "per month",
   "per_month_billed_annually": "per month, billed annually",
   "per_user": "per user",
-  "per_user_per_month": "per user / per month",
-  "per_user_per_year": "per user / per year",
+  "per_user_month": "per user / month",
   "per_user_year": "per user / year",
   "per_year": "per year",
   "percent_is_the_percentage_of_the_line_width": "% is the percentage of the line width",