Add label for time (zone) system properties

This adds a label for system properties that will affect system-wide
time / time detection logic.

The first example will be something like:
persist.time.detection_impl_version

Bug: 78217059
Test: build
Change-Id: I46044f1e28170760001da9acf2496a1e3037e48a
diff --git a/private/compat/27.0/27.0.ignore.cil b/private/compat/27.0/27.0.ignore.cil
index fe9887e..3b3f6f8 100644
--- a/private/compat/27.0/27.0.ignore.cil
+++ b/private/compat/27.0/27.0.ignore.cil
@@ -95,6 +95,7 @@
     system_boot_reason_prop
     system_update_service
     test_boot_reason_prop
+    time_prop
     timedetector_service
     timezonedetector_service
     tombstone_wifi_data_file