Suppress keystore F2FS related audit

keystore uses sqlite3. sqlite3 calls F2FS_IOC_GET_FEATURES. As
microdroid has nothing to do with that, we just suppress the audit.

Bug: 193118220
Test: atest MicrodroidHostTestCases
Change-Id: I1da00d1fd4b7e208e80a1d9bc5f49c21af684516
diff --git a/microdroid/system/private/keystore.te b/microdroid/system/private/keystore.te
index ac3ada1..be211a3 100644
--- a/microdroid/system/private/keystore.te
+++ b/microdroid/system/private/keystore.te
@@ -13,3 +13,6 @@
 
 # microdroid doesn't use keymaster HAL
 dontaudit keystore hal_keymaster_hwservice:hwservice_manager find;
+
+# microdroid isn't related to F2FS, but sqlite3 tries to query F2FS features.
+dontauditxperm keystore keystore_data_file:file ioctl F2FS_IOC_GET_FEATURES;