Update TFRT dependency to use revision
http://github.com/tensorflow/runtime/commit/4bd15f20c450ad0f4ca158aa27840425b4a5c1ce.

PiperOrigin-RevId: 375878601
Change-Id: Ibc87aab9a61bc34fb4845529bcb41b5b2c7da98f
diff --git a/third_party/tf_runtime/workspace.bzl b/third_party/tf_runtime/workspace.bzl
index 9ddfb93..dbaa2d7 100644
--- a/third_party/tf_runtime/workspace.bzl
+++ b/third_party/tf_runtime/workspace.bzl
@@ -6,8 +6,8 @@
     """Imports TFRT."""
 
     # Attention: tools parse and update these lines.
-    TFRT_COMMIT = "ac65b11964b4e0a6741c5b7997e9bc033c6750ab"
-    TFRT_SHA256 = "3efd2ee19534572f0d078bed17ddf66723f0b6092b2fb95f005b7da0fe08052a"
+    TFRT_COMMIT = "4bd15f20c450ad0f4ca158aa27840425b4a5c1ce"
+    TFRT_SHA256 = "fd0d04e8443e847c71091711aa2fcd52c5fec70e7be5e33a19b0543f6bcf5790"
 
     tf_http_archive(
         name = "tf_runtime",