* Remove ambiguity in imports - say the file extension
'less' for all instances of variables and mixins.
* Separate toast styles from drawer styles so they can be
imported separately
* associate header-action selector with its parent
(.overlay-header) not parent's parent (.overlay) so it can be imported
and rendered without the Overlay.
Change-Id: Ib7e19a440ba095d6424d35305fb41d643ca9764c
Use local imports instead given all relevant files are within the
same repository, and don't vary by configuraion.
Bug: T140807
Depends-On: If3edac9a35b346af0320c12f70c0d978a6346201
Change-Id: Ife3cc345a63aff452e93accbe0a593fbaa358732
