Remove unneeded quoting from paths in Packages file.
Remove unneeded quoting from paths in Packages file.

This quoting isn't needed, and actually causes problems when we use gs://
URLs.

BUG=chromium-os:10988
TEST=Upload prebuilt and check that Portage can download it.

Review URL: http://codereview.chromium.org/6461006

Change-Id: I8a4525bb8ff6692ec41a175cf91c41bfe3fddb3c

bpsinc-native/src_third_party_chromite,zhang0137/chromite,zhang0137/chromite,chadversary/chromiumos.chromite,chadversary/chromiumos.chromite,zhang0137/chromite,bpsinc-native/src_third_party_chromite,bpsinc-native/src_third_party_chromite,coreos/chromite,coreos/chromite,coreos/chromite