SkQP: new docker test code

`tools/skqp/docker_run_apk.sh` executes SkQP tests in an emulator

`tools/skqp/run_apk.sh` is used by `docker_run_apk.sh` and
`tools/skqp/test_apk.sh` to factor out common code.

Also: `bin/sysopen` now pipes output to `/dev/null` and doesn't block.

TODO: harmonize with test code executed by bots in `infra/skqp/`.

No-Try: true
Change-Id: Ia212a84565ff52279a845e20372a0ad7cc0726a4
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/209401
Reviewed-by: Hal Canary <halcanary@google.com>
Commit-Queue: Hal Canary <halcanary@google.com>
4 files changed