Lint to prefer lowerCamelCase for constant names. (Style Guide)

[pq]

PREFER using lowerCamelCase for constant names.

In new code, use lowerCamelCase for constant variables, including enum values.

In existing code that uses ALL_CAPS_WITH_UNDERSCORES for constants, you may continue to use all caps to stay consistent.

GOOD:

const pi = 3.14;
const defaultTimeout = 1000;
final urlScheme = new RegExp('^([a-z]+):');

class Dice {
  static final numberGenerator = new Random();
}

BAD:

const PI = 3.14;
const kDefaultTimeout = 1000;
final URL_SCHEME = new RegExp('^([a-z]+):');

class Dice {
  static final NUMBER_GENERATOR = new Random();
}