Update to regex to look for underscore delimited labels

[eliasyishak]

We have recently decided to make sure that all tool labels are underscore delimited instead of hyphens. This PR fixes the regex pattern for the tool line in the config file. Sample of what a config file looks like is shown below with one tool initialized

# INTRODUCTION
#
# This is the Flutter and Dart telemetry reporting
# configuration file.
#
# Lines starting with a #" are documentation that
# the tools maintain automatically.
#
# All other lines are configuration lines. They have
# the form "name=value". If multiple lines contain
# the same configuration name with different values,
# the parser will default to a conservative value. 

# DISABLING TELEMETRY REPORTING
#
# To disable telemetry reporting, set "reporting" to
# the value "0" and to enable, set to "1":
reporting=1

# NOTIFICATIONS
#
# Each tool records when it last informed the user about
# analytics reporting and the privacy policy.
#
# The following tools have so far read this file:
#
#   dart-tools (Dart CLI developer tool)
#   devtools (DevTools debugging and performance tools)
#   flutter-tools (Flutter CLI developer tool)
#
# For each one, the file may contain a configuration line
# where the name is the code in the list above, e.g. "dart-tool",
# and the value is a date in the form YYYY-MM-DD, a comma, and
# a number representing the version of the message that was
# displayed.
flutter_tools=2023-02-22,1

[christopherfujino]

Suggested change

	r'^([A-Za-z0-9]+_*[A-Za-z0-9]*)=([0-9]{4}-[0-9]{2}-[0-9]{2}),([0-9]+)$';
	r'^([A-Za-z0-9]+[A-Za-z0-9_]*)=([0-9]{4}-[0-9]{2}-[0-9]{2}),([0-9]+)$';

Or to simplify (if we don't mind allowing a leading underscore):

    r'^(\w+)=(\d{4}-\d{2}-\d{2}),(\d+)$';

[eliasyishak]

Good suggestion, I did initially have it that way because I wanted to only have two words in the label, like flutter and tools, and prevent something like flutter_tools_cli but that seems too restrictive in hindsight.

The very simple version though allows for underscores as the first char which i wanted to prevent

[christopherfujino]

nit about the exact regex, otherwise LGTM