Fixing wrong check being used for application status

Earlier we were relying on activity list to check is an app is
installed or not. It fails if the app only exposes widgets and
no visible activity. Hence dragging an icon to AppInfo sometimes
causes the icon to get disappear.

Bug: 33241335
Change-Id: Ieb71e298a0930dd0a831cf09bd1e998514a427fd
4 files changed