Add dng sdk 1.4 -> 1.7.1 migration compat

DNG SDK changed the method signature of a few APIs. Add an
SK_DNG_VERSION define to indicate the dng-sdk version being
used to appropriately #ifdef the differences.

Bug: b/396644977
Change-Id: Ifa9891217e979ef2b32b0cd2e79a2cc895c8ff22
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/998076
Commit-Queue: John Reck <jreck@google.com>
Reviewed-by: Noelle Scobie <nscobie@google.com>
Reviewed-by: Kaylee Lubick <kjlubick@google.com>
3 files changed