Add file context for keymaster 4.0 service.

Test: Boot the device
Change-Id: Ia468941e78803edebe311c73f424a41ac1faeaee
diff --git a/vendor/file_contexts b/vendor/file_contexts
index 38b3f1a..e2476c4 100644
--- a/vendor/file_contexts
+++ b/vendor/file_contexts
@@ -20,6 +20,7 @@
 /(vendor|system/vendor)/bin/hw/android\.hardware\.health@1\.0-service         u:object_r:hal_health_default_exec:s0
 /(vendor|system/vendor)/bin/hw/android\.hardware\.ir@1\.0-service             u:object_r:hal_ir_default_exec:s0
 /(vendor|system/vendor)/bin/hw/android\.hardware\.keymaster@3\.0-service      u:object_r:hal_keymaster_default_exec:s0
+/(vendor|system/vendor)/bin/hw/android\.hardware\.keymaster@4\.0-service      u:object_r:hal_keymaster_default_exec:s0
 /(vendor|system/vendor)/bin/hw/android\.hardware\.light@2\.0-service          u:object_r:hal_light_default_exec:s0
 /(vendor|system/vendor)/bin/hw/android\.hardware\.lowpan@1\.0-service         u:object_r:hal_lowpan_default_exec:s0
 /(vendor|system/vendor)/bin/hw/android\.hardware\.memtrack@1\.0-service       u:object_r:hal_memtrack_default_exec:s0