immersive mode: don't unconfirm a package, that's just dumb

* This is very annoying for specialized apps
* See here for a great explanation http://stackoverflow.com/a/20309721
* The fact that it doesn't even notify the user until the NEXT time they
  run it makes it completely pointless in my opinion anyway.

Change-Id: I423611efc07d467e1d81c66d58adcff331be8b38

Conflicts:

	policy/src/com/android/internal/policy/impl/ImmersiveModeConfirmation.java

(cherry picked from commit c6d0d53253519eae32517b174e5519271e6091c4)