Bump VTK to bring in text rendering changes.

Change-Id: I78bea9496b65c840454cf5bfdeac6b8f6382c375
Bring in volume rendering fixes.

Change-Id: I63b375e99a35bca3141fc37c9578b22c0f8f978a
Merge topic 'text_updates' into next

5122824a Bring in volume rendering fixes.
f371c3e1 Bump VTK to bring in text rendering changes.