Roll Flutter from b4f8d7c79296 to 896e5b332d36 (1 revision) (#1737)

diff --git a/.ci/flutter_master.version b/.ci/flutter_master.version
index 0dedab8..c9f3e69 100644
--- a/.ci/flutter_master.version
+++ b/.ci/flutter_master.version
@@ -1 +1 @@
-b4f8d7c7929648cf2e4f51fb4ab746473ff09142
+896e5b332d364cbe407966787115ce6cc4e6dde4