cros: Remove the touchable app context menu flag.

The feature has been enabled by default, so remove the flag.

Bug: 906684
Change-Id: I0ea6f282ef1054c1098fbb8b9fd4b537088db74b
Reviewed-on: https://chromium-review.googlesource.com/c/1351752
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Alex Newcomer <newcomer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#614504}
5 files changed