manifest: chmod files to set the writable permissions

In order to make chrony use NTP settings from DHCP (#412),
we need to chmod the following files to unset the writable permissions. Git tracks only the executable bit
of the permissions so when the files get pulled locally they could have the group write bit set. When that
happens we get an error like: `Cannot execute '/etc/NetworkManager/dispatcher.d/20-coreos-chrony-dhcp': writable by group or other`

manifest.yaml

@@ -33,3 +33,13 @@ postprocess:
     mkdir -p /etc/fedora-coreos-pinger/config.d /etc/zincati/config.d
     echo -e '# https://github.com/coreos/fedora-coreos-tracker/issues/163\nreporting.enabled = false' > /etc/fedora-coreos-pinger/config.d/90-disable-on-non-production-stream.toml
     echo -e '# https://github.com/coreos/fedora-coreos-tracker/issues/163\nupdates.enabled = false' > /etc/zincati/config.d/90-disable-on-non-production-stream.toml
+    # In order to make chrony use NTP settings from DHCP 
+    # (https://github.com/coreos/fedora-coreos-config/pull/412), we need 
+    # to chmod the following files to unset the writable permissions.
+    # Git tracks only the executable bit of the permissions so when
+    # the files get pulled locally they could have the group write bit set.
+    # When that happens we get an error like:
+    # `Cannot execute '/etc/NetworkManager/dispatcher.d/20-coreos-chrony-dhcp': writable by group or other`
+    chmod 755 /etc/NetworkManager/dispatcher.d/20-coreos-chrony-dhcp
+    chmod 755 /usr/libexec/coreos-chrony-helper
+    chmod 755 /usr/lib/systemd/system-generators/coreos-platform-chrony