Update Engine revision to 9aa7816315095c86410527932918c718cb35e7d6 for stable release 3.7.8 (#123114)

diff --git a/bin/internal/engine.version b/bin/internal/engine.version
index 06e3424..210e12b 100644
--- a/bin/internal/engine.version
+++ b/bin/internal/engine.version
@@ -1 +1 @@
-1837b5be5f0f1376a1ccf383950e83a80177fb4e
+9aa7816315095c86410527932918c718cb35e7d6