Use the right string and check for open in new tab

"Open in new tab in group" should show up in context menu on links
long press as well as NTP. And also the check for this should be
through FeatureUtilities.

BUG=945879

Change-Id: I2f20698c1f81729611e75944608637819fa1a6f1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1545706
Reviewed-by: Wei-Yin Chen (陳威尹) <wychen@chromium.org>
Commit-Queue: Yusuf Ozuysal <yusufo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#645907}