Refactor find and select dialogs

(This is a work in progress -- assets in particular are not final)

Use common code when showing the select and find dialogs. Both
now use similarly constructed contextual action bars and share
resources where possible. Both share a common base class so
supporting code can communicate with either.

Companion changes in frameworks/base and external/webkit

Change-Id: I62e15afd2730444985f8dbd2472df3cae351f47a
http://b/262451
12 files changed