Revert "Add APIs to allow Device Admins to change SELinux settings"

This reverts commit ab9fdc567c34ba47621ee329c302ac21cf5d8448.

Conflicts:
	core/java/android/app/admin/DeviceAdminInfo.java
	core/java/android/app/admin/DevicePolicyManager.java
	core/java/android/app/admin/IDevicePolicyManager.aidl
	core/res/res/values/symbols.xml
	services/java/com/android/server/DevicePolicyManagerService.java

Change-Id: Idb4f8daf2a3de734444417941b04b58824eb09f6