Do not encode '~' as %7E. Fixes redirect loop in chrome.

Do not encode '~' as %7E. Fixes redirect loop in chrome.

As of 155d555b83eca640, we now redirect variations on hex escapes
into their canonical form. This was causing '~' to be redirected
to %7E. However google chrome seems to canonicalize %7E back
into ~, causing a redirect loop.

RFC 3986 says ~ is unreserved, so not hex encoding it should be
fine. To quote: "For consistency, percent-encoded octets in the
ranges of...tilde (%7E) should not be created by URI producers"

Bug: T105265
Change-Id: I01556eee496e2fb540de8ff09c082c1fedddb5f7