Headline font should not be Medium type

Bug: 128986173

TL;DR;; all public TextAppearance.DeviceDefault.XXX inherits from
config_headlineFontFamilyMedium and NOT config_headlineFontFamily type
which is what sysui and framework is using. This fix overrides the
fontWeight so that the fontFamily is the only thing that is being
inherited.

Change-Id: I84500fbae0e8a613385d2665ca62dd0cd4115b56