[Telemetry] Update all clients to use chromium_config.GetTelemetryDir()

Telemetry is soon to move to Catapult. The effect will be that Telemetry will
begin to be located at src/third_party/catapult/telemetry, rather than
tools/telemetry.

This CL updates all src-side Telemetry clients to use
chromium_config.GetTelemetryDir(), which is a helper that Telemetry team will
update when the move is complete.

BUG=576374

Review URL: https://codereview.chromium.org/1582793006

Cr-Commit-Position: refs/heads/master@{#371013}
15 files changed