This CL unifies the opt-in/opt-out handling for build telemetry collections about Reclient and Ninjalog.
The user consent message will be displayed only once at the beginning of a build.
```
❯ autoninja -C out/deterministic-andorid-dbg base
*** NOTICE ***
Google-internal telemetry (including build logs, username, and hostname) is collected on corp machines to diagnose performance and fix build issues. This reminder will be shown 9 more times. See http://go/chrome-build-telemetry for details. Hide this notice or opt out by running: build_telemetry [opt-in] [opt-out]
*** END NOTICE ***
Proxy started successfully.
...
```
Bug: 345113094
Change-Id: Ie5886287c4bd20262be0ff247508ac3869441eb1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/5669094
Reviewed-by: Yiwei Zhang <yiwzhang@google.com>
Reviewed-by: Michael Savigny <msavigny@google.com>
Commit-Queue: Junji Watanabe <jwata@google.com>
Reviewed-by: Takuto Ikuta <tikuta@chromium.org>
