Files App: Add Rename to cros disks client.

This CL adds Rename method to the disk client implementation which
through dbus invokes cros disks disk renaming functionality. Before
renaming happens on the mounted disk, client will save its mount point
name for later when re-mounting will occur and try to re-mount the disk
to previous mount point name to preserve file paths.

BUG=274041
CQ-DEPEND=CL:605108

Change-Id: I40d0522cb5195940b0b949418a99e2eaca1e1041
Reviewed-on: https://chromium-review.googlesource.com/616510
Commit-Queue: Klemen Kozjek <klemenko@google.com>
Reviewed-by: Hidehiko Abe <hidehiko@chromium.org>
Reviewed-by: Tomasz Mikolajewski <mtomasz@chromium.org>
Reviewed-by: Tommy Li <tommycli@chromium.org>
Reviewed-by: Naoki Fukino <fukino@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Reviewed-by: Ilya Sherman <isherman@chromium.org>
Reviewed-by: Dan Erat <derat@chromium.org>
Cr-Commit-Position: refs/heads/master@{#497518}
29 files changed