Fix config strings in nanobench tracing

These are transient, so need to be copied.

Bug: skia:
Change-Id: Id24db0b96f343ecd034dd015da6e19ea61579b56
Reviewed-on: https://skia-review.googlesource.com/41741
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
1 file changed