[COMPLIANCE] Add Copyright and License Headers (#2027)

Co-authored-by: hashicorp-copywrite[bot] <110428419+hashicorp-copywrite[bot]@users.noreply.github.com>

addons/core/addon/helpers/time-remaining.js

@@ -1,3 +1,8 @@
+/**
+ * Copyright (c) HashiCorp, Inc.
+ * SPDX-License-Identifier: MPL-2.0
+ */
+
 import Helper from '@ember/component/helper';
 import { inject as service } from '@ember/service';
 import DurationUnitFormat from 'intl-unofficial-duration-unit-format';

addons/core/tests/integration/helpers/time-remaining-test.js

@@ -1,3 +1,8 @@
+/**
+ * Copyright (c) HashiCorp, Inc.
+ * SPDX-License-Identifier: MPL-2.0
+ */
+
 import { module, test } from 'qunit';
 import { setupRenderingTest } from 'ember-qunit';
 import { render } from '@ember/test-helpers';