Move microdroid sepolicy to system/sepolicy

Bug: 190511750
Test: boot microdroid
Change-Id: I4aa4a56e9be5103d70469c3508110a973f3e4f12
diff --git a/microdroid/system/private/attributes b/microdroid/system/private/attributes
new file mode 100644
index 0000000..991bac1
--- /dev/null
+++ b/microdroid/system/private/attributes
@@ -0,0 +1,12 @@
+hal_attribute(lazy_test);
+
+# This is applied to apps on vendor images with SDK <=30 only,
+# to exempt them from recent mls changes. It must not be applied
+# to any domain on newer system or vendor image.
+attribute mlsvendorcompat;
+
+# Attributes for property types having both system_property_type
+# and vendor_property_type. Such types are ill-formed because
+# property owner attributes must be exclusive.
+attribute system_and_vendor_property_type;
+expandattribute system_and_vendor_property_type false;