Roll Flutter from c07af53b3cb2 to 99475b1b0bee (10 revisions) (#6455)

diff --git a/.ci/flutter_master.version b/.ci/flutter_master.version
index faf70b1..a9baeda 100644
--- a/.ci/flutter_master.version
+++ b/.ci/flutter_master.version
@@ -1 +1 @@
-c07af53b3cb2182d7735f022969efb00f2ddbd27
+99475b1b0bee6ab09d0282b255c6b8c7e01ca4fe