[Files app] Fix VolumeManager unittests with MyFilesVolume enabled

Fix VolumeManager unittest by forcing the flag to be enabled and
changing the volume id to the new id.

Bug: 873539
Change-Id: Ibb230220486cd6b91eadbe7b7e0b35972a45a695
Reviewed-on: https://chromium-review.googlesource.com/c/1428001
Commit-Queue: Joel Hockey <joelhockey@chromium.org>
Auto-Submit: Luciano Pacheco <lucmult@chromium.org>
Reviewed-by: Joel Hockey <joelhockey@chromium.org>
Cr-Commit-Position: refs/heads/master@{#625403}
1 file changed