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/shell.te b/private/shell.te
index 02b01f5..8a933a5 100644
--- a/private/shell.te
+++ b/private/shell.te
@@ -74,3 +74,8 @@
 # Allow shell to start and comminicate with lpdumpd.
 set_prop(shell, lpdumpd_prop);
 binder_call(shell, lpdumpd)
+
+# Allow shell to set linker property
+userdebug_or_eng(`
+  set_prop(shell, linker_prop)
+')