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

Hi @Rik , it was mentioned in some bug comments: https://bugzilla.mozilla.org/show_bug.cgi?id=977056#c7 , https://bugzilla.mozilla.org/show_bug.cgi?id=977056#c13 , https://bugzilla.mozilla.org/show_bug.cgi?id=977056#c14 and https://bugzilla.mozilla.org/show_bug.cgi?id=977056#c24