Remove legacy SELinux policy parser.

This is essentially a cherry-pick of commit: 5efc6d6b034fe77953828e93ae6de82f49527553
but there is a discrepancy between external and internal branches.

Actual cherry-pick of commit: 06cd8124705d6cf8c09373a2a18b792efc26d7be

Change-Id: Icd693e4cda9b7fa3ab6efb6f523ff0c3c85c66ec
6 files changed