Add mac_permissions.xml file.

This was moved from external/mac-policy.git
diff --git a/Android.mk b/Android.mk
index 190ec34..119c6ef 100644
--- a/Android.mk
+++ b/Android.mk
@@ -101,5 +101,17 @@
 include $(BUILD_PREBUILT)
 
 ##################################
+include $(CLEAR_VARS)
+
+LOCAL_MODULE := mac_permissions.xml
+LOCAL_MODULE_CLASS := ETC
+LOCAL_MODULE_TAGS := optional
+LOCAL_MODULE_PATH := $(TARGET_OUT_ETC)/security
+
+LOCAL_SRC_FILES := $(LOCAL_MODULE)
+
+include $(BUILD_PREBUILT)
+
+##################################
 
 endif #ifeq ($(HAVE_SELINUX),true)