Add file contexts for OnDevicePersonalization module.

Test: Build
Bug: b/218749359
Ignore-AOSP-First: this feature is still under development.
Change-Id: Ib69e8e7098913e14b9973c65b37c88daa98b4e06
diff --git a/apex/com.android.ondevicepersonalization-file_contexts b/apex/com.android.ondevicepersonalization-file_contexts
new file mode 100644
index 0000000..9398505
--- /dev/null
+++ b/apex/com.android.ondevicepersonalization-file_contexts
@@ -0,0 +1 @@
+(/.*)?           u:object_r:system_file:s0