Removing additional rpc due to icon cache update

When launcher loads, it fetches the list of apps twice, once for
loading all-apps and again for updating icons. Instead reusing
the previously fetched apps list.
Also moving the icon loading in a separate package for further
generalization

Change-Id: Ibd2dae56e6027a31b633da030bc6b43a90b27e1b
24 files changed