Fix app selection when adding apps to app groups.

- Don't drop separate apps with the same title
- Sort case-insensitive
- Sort disabled apps to the end of the list

Change-Id: Iffadca4896468aaee5fcfd60f8776c2bb1a8ce7f
Sort disabled apps to the end of the list in privacy guard manager.

JIRA: CYAN-1703
Change-Id: Ie3c1cf0339d66405d27c06dba07cc80e4001d669