Unpin `cc` crate version on `libc-test`

[JohnTitor]

Previously, our Android jobs fail due to mismatching of API level somehow. After some debugging, it seems like alexcrichton/cc-rs#495 is the cause. I pinned the cc crate version to 1.0.52 then the test passes as expected. For context: #1765 (comment)
But generally, it'd be great if we could use the latest version of the dependency. To unpin it, we should investigate more and introduce an actual fix to the cc crate.