Label /system/usr/share/zoneinfo differently

/system/usr/share/zoneinfo is currently labeled zoneinfo_data_file,
a label shared with /data/misc/zoneinfo. However, each of these
directory locations has different security characteristics. In
particular, the files in /system/usr/share/zoneinfo must never be
writable, whereas /data/misc/zoneinfo may be written to by system_server.
Reusing the same label hides these different security characteristics.

Create a separate label for /system/usr/share/zoneinfo.

Test: Device boots and no obvious problems.
Change-Id: I8cf16ff038b06b38f77388e546d9b7a6865f7879
diff --git a/private/file_contexts b/private/file_contexts
index 37af878..991f75b 100644
--- a/private/file_contexts
+++ b/private/file_contexts
@@ -296,6 +296,7 @@
 /system/etc/selinux/plat_seapp_contexts  u:object_r:seapp_contexts_file:s0
 /system/etc/selinux/plat_sepolicy.cil       u:object_r:sepolicy_file:s0
 /system/etc/selinux/plat_and_mapping_sepolicy\.cil\.sha256 u:object_r:sepolicy_file:s0
+/system/usr/share/zoneinfo(/.*)? u:object_r:system_zoneinfo_file:s0
 /system/bin/vr_hwc               u:object_r:vr_hwc_exec:s0
 /system/bin/adbd                 u:object_r:adbd_exec:s0
 /system/bin/vold_prepare_subdirs u:object_r:vold_prepare_subdirs_exec:s0
@@ -445,7 +446,6 @@
 /data/misc/wifi/sockets(/.*)?   u:object_r:wpa_socket:s0
 /data/misc/wifi/sockets/wpa_ctrl.*   u:object_r:system_wpa_socket:s0
 /data/misc/zoneinfo(/.*)?       u:object_r:zoneinfo_data_file:s0
-/system/usr/share/zoneinfo(/.*)? u:object_r:zoneinfo_data_file:s0
 /data/misc/vold(/.*)?           u:object_r:vold_data_file:s0
 /data/misc/perfprofd(/.*)?      u:object_r:perfprofd_data_file:s0
 /data/misc/update_engine(/.*)?  u:object_r:update_engine_data_file:s0