Bump http to 0c2293062d7c1fa472f299da764a7dbb3895ee22

Changes:
```
> git log --format="%C(auto) %h %s" 2993ea5..0c22930
 https://dart.googlesource.com/http.git/+/0c22930 Add browser support for response header tests. (#716)
 https://dart.googlesource.com/http.git/+/9f1416e A browser tests for request headers. (#715)
 https://dart.googlesource.com/http.git/+/557d9a3 Support executing tests when run as a package (#714)
 https://dart.googlesource.com/http.git/+/2b4f988 Set async min version to match pinned flutter version (#713)
 https://dart.googlesource.com/http.git/+/a479221 Add browser tests for the response body. (#712)
 https://dart.googlesource.com/http.git/+/0e20ff9 Run the request body tests against the browser client. (#711)
 https://dart.googlesource.com/http.git/+/c09fb1d Run the redirect tests against the browser client. (#708)
 https://dart.googlesource.com/http.git/+/2f723b0 Use the Uri.http constructor in docs and tests (#707)
 https://dart.googlesource.com/http.git/+/346f25d add a LICENSE file; tweaks to the readmes (#709)
 https://dart.googlesource.com/http.git/+/9700bb0 Add a conformance test package for http Clients (#706)
 https://dart.googlesource.com/http.git/+/ae8a9a8 Fix the repository page for monorepoization (#705)
 https://dart.googlesource.com/http.git/+/06649af Mono (#704)

```

Diff: https://dart.googlesource.com/http.git/+/2993ea5dff5ffb066b4a35c707e7a2b8dcfa17c2~..0c2293062d7c1fa472f299da764a7dbb3895ee22/
Change-Id: I967ccd6cc1fda757696099ededc53dbbf942e6a0
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/248351
Commit-Queue: Devon Carew <devoncarew@google.com>
Reviewed-by: Kevin Moore <kevmoo@google.com>

DEPS

@@ -114,7 +114,7 @@ vars = {
   "html_rev": "f108bce59d136c584969fd24a5006914796cf213",
   "http_multi_server_rev": "35a3b947256768426090e3b1f5132e4fc23c175d",
   "http_parser_rev": "9126ee04e77fd8e4e2e6435b503ee4dd708d7ddc",
-  "http_rev": "2993ea5dff5ffb066b4a35c707e7a2b8dcfa17c2",
+  "http_rev": "0c2293062d7c1fa472f299da764a7dbb3895ee22",
   "icu_rev": "81d656878ec611cb0b42d52c82e9dae93920d9ba",
   "intl_rev": "9145f308f1458f37630a1ffce3b7d3b471ebbc56",
   "jinja2_rev": "2222b31554f03e62600cd7e383376a7c187967a1",