Start passing volume UUID to installd.

This change adds new method overloads to provide volume UUID.  The
older methods remain for now, and pass through the "null" UUID to
reference internal storage.

Follows the existing pattern where null arguments are passed as "!".

Bug: 19993667
Change-Id: Ia1b7c8550cabc13e4f6e1182eabb650f2c33e44f