Add API and TEST_API variables to recipe modules

Eventually these will be required.

Bug: b/446916327
Change-Id: I29f8f7b6a9c3ac0702d8aa7a0c3a714d9588c7ff
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/1059813
Commit-Queue: Kaylee Lubick <kjlubick@google.com>
Reviewed-by: Kaylee Lubick <kjlubick@google.com>
Auto-Submit: Rob Mohr <mohrr@google.com>
15 files changed