fix coverage tests

tests/karma-cov.conf.js

@@ -25,6 +25,12 @@ module.exports = function (config) {
       {pattern: path.resolve('./build/injector.js'), watched: false},
       {pattern: process.env.KARMA_FILE_PATTERN, watched: false}
     ],
+    customLaunchers: {
+      ChromeHeadlessNoSandbox: {
+        base: 'ChromeHeadless',
+        flags: ['--no-sandbox']
+      }
+    },
     preprocessors: {
       'build/injector.js': ['webpack'],
       'src/*.spec.ts': ['webpack', 'sourcemap']