Add support in Telemetry for specifying exact Android APK

Prior to this commit, you could not specify a path to an Android APK to run a
Telemetry test against. Desktop was the only platform that supported it.
This commit provides support support for running reference builds for the
Android platform in buildbot.

To run a Telemetry test against an exact APK, you can run the following
in tools/perf:

./run_benchmark --browser=exact --browser-executable=/path/to/my.apk benchmark

This also adds myself ([email protected]) to AUTHORS.

[email protected]
BUG=435179

Review URL: https://codereview.chromium.org/745733002

Cr-Commit-Position: refs/heads/master@{#310346}
8 files changed