mmd: allow mmd.zram.enabled shared between system_server

system_server reads mmd.zram.enabled system property to switch zram
management system between mmd and the old one.

Bug: 393481329
Test: manual

Change-Id: I0222c84152fb2538fbd04fb3e90a829970116f2e
diff --git a/private/system_server.te b/private/system_server.te
index bfe1c5e..92caa60 100644
--- a/private/system_server.te
+++ b/private/system_server.te
@@ -923,6 +923,9 @@
 # Allow system server to determine if system services are enabled
 get_prop(system_server, system_service_enable_prop)
 
+# Allow system server to read shared mmd properties
+get_prop(system_server, mmd_shared_prop)
+
 # Create a socket for connections from debuggerd.
 allow system_server system_ndebug_socket:sock_file create_file_perms;