SkQP: run a single test

PLEASE NOTE:  Instructions on running `am instrument` for the
SkQP APK have changed.

To run a single test, see the section "Running a single test"
in `tools/skqp/README.md`.

No-Try: true
Change-Id: I0a2cbc47755929d6c6a927a3591ff98046779c77
Reviewed-on: https://skia-review.googlesource.com/108780
Reviewed-by: Derek Sollenberger <djsollen@google.com>
Commit-Queue: Hal Canary <halcanary@google.com>
(cherry picked from commit f637cc01f8f28d920a1d5b792193e97e8dd63e42)
Reviewed-on: https://skia-review.googlesource.com/109166
Reviewed-by: Hal Canary <halcanary@google.com>
5 files changed