[Files.app] Disable the suggest apps dialog by default.

The suggest apps dialog has been temporary disabled while the m31 branch is cut. This patch is revert of r226759.

BUG=313875
TEST=manually tested, test passes
TBR=mtomasz@chromium.org
# TBRing for reverting

Review URL: https://codereview.chromium.org/57553002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@232715 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 232715