Revert "Minimal test harness for iOS (#13029)" (#18631)

This reverts commit 0622b051b63b399838eb7956bed97d76fc8bdf77.
https://dart.googlesource.com/external/github.com/flutter/engine/+/17737e6fd4ec28d83ecc1f159e50f9330f5befb1
diff --git a/commits.json b/commits.json
index 4540e06..721d244 100644
--- a/commits.json
+++ b/commits.json
@@ -1,5 +1,5 @@
 {
-  "external/github.com/flutter/engine":"e0487e75e96c9fc0f56a7b3c70421e1b440c7167",
+  "external/github.com/flutter/engine":"17737e6fd4ec28d83ecc1f159e50f9330f5befb1",
   "external/github.com/flutter/flutter":"a1636b6fef2ebe7840ba6dc1b3f9d77095ef3b45",
   "sdk":"a2b5373eaac0fa36ac8fdda939b8fa26bd7d5633"
 }
\ No newline at end of file