update_engine: Add chronos permission to call `IsFeatureEnabled` DBus API

BUG=chromium:1278079
TEST=CQ

Change-Id: Ia867031f03f25c4a0e0c4fa5d7e18f59c1959c1e
Reviewed-on: https://chromium-review.googlesource.com/c/aosp/platform/system/update_engine/+/3489786
Tested-by: Jae Hoon Kim <kimjae@chromium.org>
Auto-Submit: Jae Hoon Kim <kimjae@chromium.org>
Commit-Queue: Jae Hoon Kim <kimjae@chromium.org>
Reviewed-by: Henry Barnor <hbarnor@chromium.org>
Commit-Queue: Henry Barnor <hbarnor@chromium.org>

UpdateEngine.conf

diff --git a/UpdateEngine.conf b/UpdateEngine.conf
index 8428909..ae22ada 100644
--- a/UpdateEngine.conf
+++ b/UpdateEngine.conf
@@ -74,6 +74,9 @@
            send_member="ToggleFeature"/>
     <allow send_destination="org.chromium.UpdateEngine"
            send_interface="org.chromium.UpdateEngineInterface"
+           send_member="IsFeatureEnabled"/>
+    <allow send_destination="org.chromium.UpdateEngine"
+           send_interface="org.chromium.UpdateEngineInterface"
            send_member="GetDurationSinceUpdate"/>
     <allow send_destination="org.chromium.UpdateEngine"
            send_interface="org.chromium.UpdateEngineInterface"