Dontaudit unneeded denials.

These denials are intermittent and unnecessary.  Hide them while we
investigate how to properly fix the issue.

Bug: 131096543
Bug: 132093726
Test: Build
Change-Id: I1950c10a93d183c19c510f869419fcfccd5006d2
(cherry picked from commit 654ceeb93f7d504a2496d2357e7a954a96b8d9df)
diff --git a/private/vold_prepare_subdirs.te b/private/vold_prepare_subdirs.te
index e6df48d..348d3ce 100644
--- a/private/vold_prepare_subdirs.te
+++ b/private/vold_prepare_subdirs.te
@@ -32,3 +32,5 @@
     system_data_file
     vold_data_file
 }:file { getattr unlink };
+
+dontaudit vold_prepare_subdirs { proc unlabeled }:file r_file_perms;