Add file contexts for Auxiliary module.

Test: loaded to an AVD
Bug: b/210728915
Ignore-AOSP-First: this feature is developed in an internal branch
Change-Id: I000ec62b5aa8fba1fbf2ac5f65ae5deb3ebe9ff7
diff --git a/apex/com.android.auxiliary-file_contexts b/apex/com.android.auxiliary-file_contexts
new file mode 100644
index 0000000..9398505
--- /dev/null
+++ b/apex/com.android.auxiliary-file_contexts
@@ -0,0 +1 @@
+(/.*)?           u:object_r:system_file:s0