Merge "Adding optional block to run before screenshot" into udc-dev am: a6550a83 am: 3523cdac

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23356977



Change-Id: If8c5a3b0c9e5e60d2013864934ab51897ea93773
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>