Completely customize angular build files hashing.

extra-webpack.config.js

module.exports = function (config) {
  const buzz = `${Date.now()}.buzz`; //change the value to what do you want
  if (config.output.filename) {
    const splicedOut = config.output.filename.split('.');
    config.output.filename = `${splicedOut.slice(0, -1).join('.')}.${buzz}.${splicedOut.slice(-1).join('.')}`;
  }
  if (config.output.chunkFilename) {
    const splicedOut = config.output.chunkFilename.split('.');
    config.output.chunkFilename = `${splicedOut.slice(0, -1).join('.')}.${buzz}.${splicedOut.slice(-1).join('.')}`;
  }
  if (Array.isArray(config.module.rules)) {
    config.module.rules.forEach(rule => {
      if (rule.options && rule.options.name) {
        const splicedOut = rule.options.name.split('.');
        rule.options.name = `${splicedOut.slice(0, -1).join('.')}.${buzz}.${splicedOut.slice(-1).join('.')}`;
      }
    });
  }
  if (Array.isArray(config.plugins)) {
    config.plugins.forEach(plugin => {
      if (plugin.options && plugin.options.filename) {
        const splicedOut = plugin.options.filename.split('.');
        plugin.options.filename = `${splicedOut.slice(0, -1).join('.')}.${buzz}.${splicedOut.slice(-1).join('.')}`;
      }
      if (plugin.options && plugin.options.chunkFilename) {
        const splicedOut = plugin.options.chunkFilename.split('.');
        plugin.options.chunkFilename = `${splicedOut.slice(0, -1).join('.')}.${buzz}.${splicedOut.slice(-1).join('.')}`;
      }
    });
    config.plugins.push({
      apply(compiler) {
        compiler.hooks.compilation.tap('build-angular', compilation => {
          compilation.mainTemplate.hooks.assetPath.tap('build-angular', (filename, data) => {
            const assetName = typeof filename === 'function' ? filename(data) : filename;
            if (!data.chunk || data.chunk.name !== 'polyfills-es5') {
              return assetName;
            }
            const splicedOut = assetName.split('.');
            const isMap = assetName && assetName.endsWith('.map');
            if (isMap) {
              return `${splicedOut.slice(0, -2).join('.')}.${buzz}.${splicedOut.slice(-2).join('.')}`;
            }
            return `${splicedOut.slice(0, -1).join('.')}.${buzz}.${splicedOut.slice(-1).join('.')}`;
          });
        });
      }
    });
  }

  return config;
};

This solution required package @angular-builders/custom-webpack and you must be modified the file angular.json to look like this.

{
  ...
  "architect": {
    ...
    "build": {
      ...
      "builder": "@angular-builders/custom-webpack:browser",
      "options": {
        ...
        "customWebpackConfig": {
          "path": "./extra-webpack.config.js"
        }
      }
    }
  }
}