Update git hash for flutter/devtools (#496)

Updates DevTools commit hash to [405689bc49f9c7ae0d7ca77b3d9b0f698745989b](flutter/devtools@405689b).

This incorporates flutter/devtools#10016 which migrates DevTools from `flutter/material.dart` to `material_ui/material_ui.dart` for flutter/flutter#192957.

Author: johnpryan

registry/flutter_devtools.test

@@ -7,7 +7,7 @@ fetch=git -c core.longPaths=true clone https://github.com/flutter/devtools.git t
 # NOTE: this commit hash should also match the hash in flutter_devtools_analysis.test.
 # The analysis and testing for DevTools have been split into two different
 # registry to speed up performance.
-fetch=git -c core.longPaths=true -C tests checkout adce730d2817b70849d76d0257996a8cb273dd5d
+fetch=git -c core.longPaths=true -C tests checkout 405689bc49f9c7ae0d7ca77b3d9b0f698745989b
 
 setup.linux=./tool/flutter_customer_tests/setup.sh >> output.txt
 

registry/flutter_devtools_analysis.test

@@ -7,7 +7,7 @@ fetch=git -c core.longPaths=true clone https://github.com/flutter/devtools.git t
 # NOTE: this commit hash should also match the hash in flutter_devtools.test.
 # The analysis and testing for DevTools have been split into two different
 # registry to speed up performance.
-fetch=git -c core.longPaths=true -C tests checkout adce730d2817b70849d76d0257996a8cb273dd5d
+fetch=git -c core.longPaths=true -C tests checkout 405689bc49f9c7ae0d7ca77b3d9b0f698745989b
 
 # Mock generation required. Otherwise the test code will show analysis errors.
 setup.linux=./tool/flutter_customer_tests/setup.sh >> output.txt