Build SDK using prebuilts/devtools.

Cleans up some unused/renamed files:
- sdk_only_whitelist is better named windows_sdk_whitelist.
- a few product.mk dependencies should not be listed here
  any more but in the sdk/product.mk instead (which they were.)

Change-Id: Ifad3049321c8ec4edd8b94b83e570eebba442e7d