[antlir2][package] inherit systemd configuration

Summary:
Packages should inherit the systemd setting from however they are being brought
into the build, just like how the OS is inherited.

Reviewed By: naveedgol

Differential Revision: D65155951

fbshipit-source-id: ed0956c2dcdcf12d080447b4d50c3b08b939fddf

antlir/antlir2/bzl/package/cfg.bzl

@@ -45,7 +45,6 @@ def _package_cfg_impl(platform: PlatformInfo, refs: struct, attrs: struct) -> Pl
         constraints = constraints,
         refs = refs,
         attrs = attrs,
-        overwrite = True,
     )
 
     if is_facebook:

antlir/antlir2/cfg/systemd/defs.bzl

@@ -3,7 +3,12 @@
 # This source code is licensed under the MIT license found in the
 # LICENSE file in the root directory of this source tree.
 
-def _transition(*, constraints, refs: struct, attrs: struct, overwrite: bool):
+def _transition(
+        *,
+        constraints,
+        refs: struct,
+        attrs: struct,
+        overwrite: bool = False):
     setting = refs.systemd_setting[ConstraintSettingInfo]
     if attrs.systemd and (
         (setting.label not in constraints) or