Returns a service parse error on overrides across the treble boundary.

Also includes new --out_<partition> flags for
  system,system_ext,product,vendor,odm
to allow host_init_verifier to work with a collection of init rc files.

Test: host_init_verifier --out_system=... --out_vendor=...
      where vendor contains an init rc file that overrides a service
      present in system. Observe parse failure and non-zero exit.
Bug: 163089173
Change-Id: I520fef613e0036df8a7d47a98d47405eaa969110
diff --git a/init/service.cpp b/init/service.cpp
index 7b98392..766eb5d 100644
--- a/init/service.cpp
+++ b/init/service.cpp
@@ -154,6 +154,7 @@
                  .priority = 0},
       namespaces_{.flags = namespace_flags},
       seclabel_(seclabel),
+      subcontext_(subcontext_for_restart_commands),
       onrestart_(false, subcontext_for_restart_commands, "<Service '" + name + "' onrestart>", 0,
                  "onrestart", {}),
       oom_score_adjust_(DEFAULT_OOM_SCORE_ADJUST),