[flutter_releases] Flutter beta 2.12.0-4.1.pre Framework Cherrypicks (#101771)

* 'Create candidate branch version flutter-2.13-candidate.0 for beta'

* 'Update Engine revision to 499984f99cfe01e3b69d962ec4847f70c4317694 for beta release 2.12.0-4.1.pre'

* update candidate version
diff --git a/bin/internal/engine.version b/bin/internal/engine.version
index 7a0d49e..4bb41dd 100644
--- a/bin/internal/engine.version
+++ b/bin/internal/engine.version
@@ -1 +1 @@
-c34164517800e8c352df350d10da494f34c302de
+499984f99cfe01e3b69d962ec4847f70c4317694
diff --git a/bin/internal/release-candidate-branch.version b/bin/internal/release-candidate-branch.version
new file mode 100644
index 0000000..91ca740
--- /dev/null
+++ b/bin/internal/release-candidate-branch.version
@@ -0,0 +1 @@
+flutter-2.13-candidate.0