Bug 977056 - [Dialer] Visual discrepancies: Call ended view under conference call participants list

This should exist in a mock HTML file. If you need an example of how to load a fragment into a mock HTML file, check this out: https://github.com/mozilla-b2g/gaia/blob/edbce405a3dc087520df73207e204dc9a8d0f803/apps/communications/dialer/test/unit/call_info_test.js#L58-L70