Move growfs and autoupdates into `tier-1/usr` overlay, use preset

Instead of having postprocessing scripts for these, add
them to the overlay. Also instead of hand rolling static systemd
enablement, add and use a preset file for them instead.

(This also makes it easier for downstream container images
 to rerun the presets if they wanted to)

Signed-off-by: Colin Walters <walters@verbum.org>

tier-1/autoupdates.yaml

@@ -1,9 +0,0 @@
-# Enable automatic updates by default
-postprocess:
-  - |
-    #!/usr/bin/env bash
-    set -euo pipefail
-    target=/usr/lib/systemd/system/default.target.wants
-    mkdir -p $target
-    set -x
-    ln -s ../bootc-fetch-apply-updates.timer $target

tier-1/generic-growfs.yaml

@@ -1,12 +0,0 @@
-add-files:
-  - - bootc-generic-growpart
-    - /usr/libexec/bootc-generic-growpart
-  - - bootc-generic-growpart.service
-    - /usr/lib/systemd/system/bootc-generic-growpart.service
-
-postprocess:
-  - |
-    #!/bin/bash
-    set -euo pipefail
-    mkdir -p /usr/lib/systemd/system/local-fs.target.wants
-    ln -s ../bootc-generic-growpart.service /usr/lib/systemd/system/local-fs.target.wants/bootc-generic-growpart.service

tier-1/manifest.yaml

@@ -3,12 +3,9 @@ recommends: true
 
 include:
   - ../tier-x/manifest.yaml
-  - autoupdates.yaml
   - networking-tools.yaml
   - system-configuration.yaml
   - coreos-user-experience.yaml
-  - persistent-journal.yaml
-  - generic-growfs.yaml
 
 packages:
   # Include and set the default editor

tier-1/usr/lib/systemd/system-preset/05-bootc.preset

@@ -0,0 +1,7 @@
+# Our fallback
+enable bootc-generic-growpart.service
+
+# We enable this by default just so we can say we have automatic
+# updates on by default, like CoreOS. It's very much intended
+# to be tweaked or replaced outside of trivial scenarios though.
+enable bootc-fetch-apply-updates.timer