This reverts commit b7f5aef1.

* add web-renderer option to flutter test. run web tests with this option

* remove debug lines

* add autodetect false

* fix typo

Revert "Pass --local-engine* flags from dev/bots/test.dart down to `pub test` via env variables (#71721)" (#72141)

This reverts commit 4300226a.

Reason for revert: The original PR correctly passes down the local
engine flags to subprocesses of the tests. Though this causes issues
because some tests assume a specific target but do not modify the
value for `--local-engine` (which is set to `host_debug`) to reflect
that.

See more discussion here:

    https://github.com/flutter/flutter/pull/71721#issuecomment-743218994

Adds a new Luci test shard that runs flutter/plugins tests.

For now only the analysis phase of the flutter/plugins test suite is executed.

Manual invocation on Luci completed successfully: https://luci-milo.appspot.com/raw/build/logs.chromium.org/flutter/led/amirha_google.com/3210bb2dac01fca71b7db04dda02fa6ccd4df025afd55abea1970d26087d4962/+/annotations

Migrate flutter_localizations to null safety.

* Move web integration tool tests to web.shard

Web integration tool tests depend on DDC changes in SDK. This change
moves them to a separate shard and subshard so CI bot configurations
can run them separately.

In particular, with will allow running those tests on dart CI flutter
HHH web bot instead of a non-web one, allowing early detection and easy
classification of issues caused by SDK changes as VM- or Web related.

* Enabled verbose mode for flaky web_tool_tests

* Split out the test changes to be commited first

This reverts ae0a9cb5 and therefore relands #69629.

Additionally, `flutter update-packages --force-upgrade` has been run to update `pubspec.yaml` to resolve the analyze test failures.

This reverts commit ada6b7e5.

For the ease of code reviews, this only includes minimal code from
MetricPoint, GoogleBenchmarksParser, and their unit tests.

See go/flutter-metrics-center-migration for the overall plan.

* start and stop chromedriver once per sub-shard; do not wait for it to quit

* enable web_long_running_tests but keep them as flaky

Disable null safety auto-detection for the web