Fixing static instance of Indexer being created in the model

Indexer depends on the locale and should be created when ever the config
changes. Moving the widget indexing to the adapter (similar to allApps)
which gets created whenever the activity is recreated.
This fixes the bug where widgets indexing breaks if locale changes while launcher
process is alive
Also fixing the bug in widget model cloning where the HashMap was not cloning
the underlying ArrayList

Change-Id: I7dbe6290e73299c4c07aa7fa564077a2649e1a4c