Introduce vendor_microdroid_file for microdroid vendor image

In AVF, virtualizationmanager checks the selinux label of given disk
image for proving whether the given image is edited maliciously.
Existing one(vendor_configs_file, /vendor/etc/*) was too wide to use for this purpose.

Bug: 285854379
Test: m
Change-Id: I6c966c92b238a2262d2eb7f41041ed4c359e9e0a
diff --git a/private/virtualizationmanager.te b/private/virtualizationmanager.te
index d6f0e19..871d3f2 100644
--- a/private/virtualizationmanager.te
+++ b/private/virtualizationmanager.te
@@ -94,6 +94,9 @@
   allow virtualizationmanager shell_data_file:file open;
 ')
 
+# Allow virtualizationmanager to read microdroid related files in vendor partition
+r_dir_file(virtualizationmanager, vendor_microdroid_file)
+
 # Allow reading files under /proc/[crosvm pid]/, for collecting CPU & memory usage inside VM.
 r_dir_file(virtualizationmanager, crosvm);