Revert "Remove borked custom font size option"

This reverts commit cba0b549a588e3e89914fb4805cf9ab18d075aed.

Conflicts:
	res/xml/display_settings.xml
	src/com/android/settings/DisplaySettings.java

Change-Id: Ia26f7c146c7a0feea5a7759913f4158a5474a85e