Enforce that projects are in docs-tip-of-tree

This checks that any project with API tracking enabled can be found in docs-tip-of-tree/build.gradle unless it has been opted-out of docs with `doNotDocumentReason`.

This is to ensure that any docs errors are caught during developement and not at release time when the project is added to docs-public/build.gradle.

Bug: 289373390
Test: All projects with `doNotDocumentReason` added were found by running `./gradlew checkDocsTipOfTree` locally
Change-Id: I5d1fc4f6d3b54df9bf2ec67e76c8dcd5e150bacc
diff --git a/camera/camera-camera2-pipe-integration/build.gradle b/camera/camera-camera2-pipe-integration/build.gradle
index 7c9b212..23cd759 100644
--- a/camera/camera-camera2-pipe-integration/build.gradle
+++ b/camera/camera-camera2-pipe-integration/build.gradle
@@ -113,4 +113,5 @@
             "and reliable camera foundation that enables great camera driven experiences across " +
             "all of Android."
     metalavaK2UastEnabled = true
+    doNotDocumentReason = "Not shipped externally"
 }