Remove legacy smack support, keep upstream smack support

Remove legacy smack support, keep upstream smack support

This commit reverts four commits.
There was a need for additional minor changes to make it work.

Revert "GetConnectionCredentials - add smack support"
This reverts commit 13d888ca95c75c14a4919b36cc0a15979fb1d42b.

Revert "packaging: enable Smack support"
This reverts commit 54f95c99cf4d53f5566511fc0cdc21b230909b29.

Revert "Enforce smack policy from conf file"
This reverts commit 1d028039f5d34de8a1224d2ad0d8bc75b3da3ca4.

Revert "Enable checking of smack context from DBus interface"
This reverts commit 7af23db240c54e9923c76234b7e9c7a243d2d428.

Change-Id: I4bf7ce8d43717e1deb5d980f87be39220922b422