Declare "role/configs.validator" binding.

It defines who is allowed to call LUCI Config validation API to
validate this LUCI project's configs. This is usually done by
presubmit jobs, and thus configs.validator role is assigned to
try job task accounts.

Previously this ACL was defined in the global "config-validation"
group. It is deprecated and being replaced with per-project ACLs
defined in per-project configs (like in this CL).

There's still a global ACL to allow any googler to call
the validation API in any LUCI project they are allowed to see.
Thus the per-project binding applies only to service accounts
(they are not googlers).

Note that this CL was generated semi-automatically and reviewers are
picked automatically based on OWNERS file.

Bug: chromium:1068817
Change-Id: Iadd19a74e3b0bce330ee0d6fd29046ab03d5c2cb
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3276460
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>

infra/config/generated/realms.cfg

@@ -14,6 +14,10 @@ realms {
     role: "role/configs.reader"
     principals: "group:all"
   }
+  bindings {
+    role: "role/configs.validator"
+    principals: "user:angle-try-builder@chops-service-accounts.iam.gserviceaccount.com"
+  }
   bindings {
     role: "role/logdog.reader"
     principals: "group:all"

infra/config/main.star

@@ -59,6 +59,10 @@ luci.project(
         ),
     ],
     bindings = [
+        luci.binding(
+            roles = "role/configs.validator",
+            users = "angle-try-builder@chops-service-accounts.iam.gserviceaccount.com",
+        ),
         luci.binding(
             roles = "role/swarming.poolOwner",
             groups = ["project-angle-owners", "mdb/chrome-troopers"],