Keystore libselinux rust bindings.

Provide safe wrappers around the libselinux API needed for keystore.
 * getcon
 * selinux_check_acces
 * selabel_lookup

Test: keystore2_selinux_test
Test: keystore2_selinux_rust_bindings_host_test
Bug: 159466840
Change-Id: I73b4aa2e1da9b477965b10927eba069e6346ce6e
diff --git a/keystore2/selinux/TEST_MAPPING b/keystore2/selinux/TEST_MAPPING
new file mode 100644
index 0000000..0e68257
--- /dev/null
+++ b/keystore2/selinux/TEST_MAPPING
@@ -0,0 +1,7 @@
+{
+  "presubmit": [
+    {
+      "name": "keystore2_selinux_test"
+    }
+  ]
+}