Update OWNERS files for code-owners plugin

Syntax updates based on
https://android-review.googlesource.com/plugins/code-owners/Documentation/backend-find-owners.html#syntax

Bug: 87716
Fixed: 86540
Change-Id: I1684cd0c580ab78464db60554e2e08f313aceea6
Reviewed-on: https://fuchsia-review.googlesource.com/c/infra/recipes/+/593581
Reviewed-by: Nathan Mulcahey <nmulcahey@google.com>
Commit-Queue: Auto-Submit <auto-submit@fuchsia-infra.iam.gserviceaccount.com>
Fuchsia-Auto-Submit: Oliver Newman <olivernewman@google.com>
(cherry picked from commit dfbe02ad482e518a37ef311915a1f929bb56c272)
Reviewed-on: https://fuchsia-review.googlesource.com/c/infra/recipes/+/602183
Reviewed-by: Oliver Newman <olivernewman@google.com>
diff --git a/CRITICAL_OWNERS b/CRITICAL_OWNERS
index 46fd049..e2aee0a 100644
--- a/CRITICAL_OWNERS
+++ b/CRITICAL_OWNERS
@@ -1,8 +1,9 @@
 # Owners of the critical parts of this repository.
 # This file is meant to be included as needed using the syntax:
-# file://CRITICAL_OWNERS (this form must be used with per-file)
-# TODO(fxb/38171): Use `include` imports instead of `file:`, once the recipe
-# roller supports it.
+#
+# set noparent
+# include /CRITICAL_OWNERS
+
 # Keep sorted.
 atyfto@google.com
 garymm@google.com
diff --git a/OWNERS b/OWNERS
index 33f7044..2eb6cc7 100644
--- a/OWNERS
+++ b/OWNERS
@@ -1,2 +1,4 @@
 # No top-level owners intentionally.
-per-file CRITICAL_OWNERS = file://CRITICAL_OWNERS
+*
+
+per-file CRITICAL_OWNERS=file:/CRITICAL_OWNERS
diff --git a/recipes/fuchsia/OWNERS b/recipes/fuchsia/OWNERS
index 45eca18..50ca263 100644
--- a/recipes/fuchsia/OWNERS
+++ b/recipes/fuchsia/OWNERS
@@ -1,2 +1,3 @@
 # Critical code is owned by critical owners.
-file://CRITICAL_OWNERS
+set noparent
+include /CRITICAL_OWNERS
diff --git a/recipes/fuchsia_roller.expected/OWNERS b/recipes/fuchsia_roller.expected/OWNERS
index 45eca18..50ca263 100644
--- a/recipes/fuchsia_roller.expected/OWNERS
+++ b/recipes/fuchsia_roller.expected/OWNERS
@@ -1,2 +1,3 @@
 # Critical code is owned by critical owners.
-file://CRITICAL_OWNERS
+set noparent
+include /CRITICAL_OWNERS
diff --git a/recipes/sdk.expected/OWNERS b/recipes/sdk.expected/OWNERS
index 45eca18..50ca263 100644
--- a/recipes/sdk.expected/OWNERS
+++ b/recipes/sdk.expected/OWNERS
@@ -1,2 +1,3 @@
 # Critical code is owned by critical owners.
-file://CRITICAL_OWNERS
+set noparent
+include /CRITICAL_OWNERS