Add SELinux policies for traced readonly properties

Added a traced config property context for all traced sysprops that
are readonly. Added the ro.traced.hypervisor system property to this
context.

Test: build Android
Bug: 391958400
Change-Id: I145d882eb54268d88b0c4a107c26cc746365e22c
diff --git a/private/traced.te b/private/traced.te
index 1aaf0d1..619a55b 100644
--- a/private/traced.te
+++ b/private/traced.te
@@ -56,6 +56,8 @@
 # Allow traced to detect if a process is frozen (b/381089063).
 allow traced cgroup_v2:file r_file_perms;
 
+# Allow traced/traced_relay to read the traced config properties.
+get_prop(traced, traced_config_prop)
 # Allow traced_relay to read the relay port being used
 get_prop(traced, traced_relay_relay_port_prop)