libweave: base::Value refactor (1/n) Rename unit test utility test::CreateValue to test::CreateUniquePtrValue so that (in next CL of the series) I will add base::CreateValue which returns a base::Value directly (not wrapped in std::unique_ptr). test::CreateUniquePtrValue is only kept for the migration and should be removed eventually. BUG=chromium:1099111 TEST=FEATURES=test emerge-hatch libweave Change-Id: Icfde0cb7cbc77c6b2085245f348f8ff07a0a66e1 Reviewed-on: https://chromium-review.googlesource.com/c/weave/libweave/+/3312867 Tested-by: Grace Cham <[email protected]> Reviewed-by: Qijiang Yūki Ishii <[email protected]> Reviewed-by: Hidehiko Abe <[email protected]> Commit-Queue: Grace Cham <[email protected]>