Remove uses of Skia containers in sample code

Remove uses of containers defined in SkTempaltes.h from the
sample code.

Change-Id: I50b3599cae39d7442fecf67ab559814a709f5df4
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/595117
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
3 files changed