Traces: Add a device arg to restricted_trace_perf In case of multiple available devices, we can use either this argument or setting $ANDROID_SERIAL to select the device to run tests on. * Added the option to run restricted_trace_perf with more than one connected device. * The device serial can be entered either by using the --device arg or setting $ANDROID_SERIAL. If both are used at the same time, the former has more priority. * Neither is required if there is only one connected device. Bug: angleproject:6970 Change-Id: Id80398b82ea5b905f3dbfa4651d5f5246a3ccbe8 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3615082 Reviewed-by: Cody Northrop <cnorthrop@google.com> Commit-Queue: Amirali Abdolrashidi <abdolrashidi@google.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>