This attribute was added in Ia0f601c1d5. Use it instead of
extracting the information from the SVG.
Change-Id: Ib6d6f4c9480ae00ccb2977b57c7b93de8ebb03f2
If a symbol has "backgroundPosition" set to true, adjust
its vertical position in the button, according to the
vertical-align property on the SVG, by adding a
background-position property on its CSS rule.
Also set "backgroundPosition" to true for a number of
symbols and generate a new CSS file.
Bug: T123397
Change-Id: Ic9bbb65d2bedf38f569d8922599a2e3d2575f153
Also produces a CSS file for the symbol buttons, using the
SVG filenames. Gets the list of symbols from symbols.json.
Bug: T118660
Change-Id: Iaa792418d870a7e266b6455ef037994e31278278
