Define sepolicy with property for linker

To support linker-specific property, sys.linker.* has been defined as
linker_prop. This will have get_prop access from domain so all binaries
can start with linker using proper property access level.

Bug: 138920271
Test: m -j && Confirmed from cuttlefish that get_prop errors are no longer found
Change-Id: Iaf584e0cbdd5bca3d5667e93cf9a6401e757a314
diff --git a/private/property_contexts b/private/property_contexts
index d1a97d9..55445ec 100644
--- a/private/property_contexts
+++ b/private/property_contexts
@@ -23,6 +23,7 @@
 ro.hw.                  u:object_r:system_prop:s0
 sys.                    u:object_r:system_prop:s0
 sys.cppreopt            u:object_r:cppreopt_prop:s0
+sys.linker.             u:object_r:linker_prop:s0
 sys.lpdumpd             u:object_r:lpdumpd_prop:s0
 sys.powerctl            u:object_r:powerctl_prop:s0
 sys.usb.ffs.            u:object_r:ffs_prop:s0