tweak new gradebook individual view name

closes CNVS-12541

test plan:
- enable the new gradebook view and go to it
- the name at the top should be "Gradebook: Individual View"

Change-Id: Icd72afc1fc8100f10cd3c43d7e9ecdf5fef56cb7
Reviewed-on: https://gerrit.instructure.com/33714
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Cameron Matheson <cameron@instructure.com>
QA-Review: Amber Taniuchi <amber@instructure.com>
Product-Review: Simon Williams <simon@instructure.com>