meson: add Debian-specific PAM file and use it when os_type is debian

In Debian and derivatives PAM uses different syntax, so add an
alternative PAM config file, and install it instead of the default
one if the os_type is debian. We have been using this PAM config
in Debian and derivatives since pretty much forever.

data/meson.build

@@ -21,13 +21,21 @@ configure_file(
 )
 
 if enable_pam
-  configure_file(
-    input: 'polkit-1.in',
-    output: '@BASENAME@',
-    configuration: pam_conf,
-    install: true,
-    install_dir: pam_prefix,
-  )
+  if os_type == 'debian' and pam_include == ''
+    install_data(
+      'polkit-1.debian',
+      rename: 'polkit-1',
+      install_dir: pam_prefix
+    )
+  else
+    configure_file(
+      input: 'polkit-1.in',
+      output: '@BASENAME@',
+      configuration: pam_conf,
+      install: true,
+      install_dir: pam_prefix,
+    )
+  endif
 endif
 
 if not get_option('libs-only')

data/polkit-1.debian

@@ -0,0 +1,8 @@
+#%PAM-1.0
+
+@include common-auth
+@include common-account
+@include common-password
+session       required   pam_env.so readenv=1 user_readenv=0
+session       required   pam_env.so readenv=1 envfile=/etc/default/locale user_readenv=0
+@include common-session-noninteractive