manifest: Use forked chromite repository.

This CL is changing the chromite repository that will be checked-out and
used for builds. Apart from that it is also using the head of
release-R77-12371.B for chromite repository instead of using
a particular commit. This repository can be used for carrying patches on
top of ChromeOS chromite repo.

BUG=b/171561057
TEST=repo init and sync

Change-Id: I931c7590a641a614e4a7a3faaa9ec43033e7f906
Reviewed-on: https://cos-review.googlesource.com/c/cos/manifest/+/12930
Reviewed-by: Robert Kolchmeyer <rkolchmeyer@google.com>
Tested-by: Vaibhav Rustagi <vaibhavrustagi@google.com>
diff --git a/external_full.xml b/external_full.xml
index 43141ab..545f2f1 100644
--- a/external_full.xml
+++ b/external_full.xml
@@ -24,9 +24,6 @@
   </notice>
 
   <!-- mirrored cros_sdk dependencies -->
-  <project path="chromite"
-           name="mirrors/cros/chromiumos/chromite"
-           revision="acf477687f5d03eeaac0f01f0486fe5e83640a06" />
   <project path="chromite/infra/proto"
            name="mirrors/cros/chromiumos/infra/proto"
            revision="4bcb4b7260bf9b98f93f5c3be79564c9ab206ce9" />
@@ -98,6 +95,10 @@
   <project path="src/third_party/chromiumos-overlay"
            name="third_party/overlays/chromiumos-overlay" />
 
+  <!-- forked cros_sdk dependencies -->
+  <project path="chromite"
+           name="third_party/chromite" />
+
   <repo-hooks enabled-list="pre-upload"
            in-project="cos/repohooks" />