Implement Path.approximate and add PathMeasure support

PathMeasure is needed to use the trimPath* properties in drawables.
These properties are used in the vector drawable for indeterminate
progress bars in Material so this is needed to be able to render them
correctly in the preview.
PathMeasure makes use of Path.approximate to calculate which segments to
paint.

Change-Id: Ic513f0a30a6aac0317f7c13cd75e9154c37405c8