GAL support

* Provides GAL autocomplete in email address fields in message composition.

General TODO list:
UI: Implement divider in adapter, not in GAL provider
UI: Use listview_separator for divider
UI: Clean up strings, move all to resources
UI: Only have one GAL lookup in flight at any time
UI: Unit tests

GAL: Use side channel for status, not a row
GAL: Shorten timeout for interactive GAL lookup
GAL: Make watchdogs work
GAL: Figure out why some calls never return (conn pool exhaustion?)
GAL: Unit tests

Bug: 2249514
Change-Id: I513e25628bc2f5ed0920e0ee509cd598b1817b3a
7 files changed