Fix issue #3306021 NPE at android.app.AlertDialog.getDefaultDialogTheme(AlertDialog.java)

It looks like the dialog fragment was not being removed along with
the containing fragment.  The containing fragment now checks for
when it is being removed and removes its dialog fragment at that
point.

Also fix issue #3340766 NPE at
com.android.settings.applications.RunningProcessesView.startServiceDetailsActivity

We need to check if the running processes view is still attached to its
owner, since we clear owner when it is paused.

In addition, fix a bug where ManageApplications was not persisting
its "show background processes" state, and remove the icons from
its menu items to make them more understandable in the action bar.

Change-Id: I4498ef92023eb60f90758ff18d8eed7b41af79b0