37900 Listen to ExtensionEvent instead of TimelineEvent

37958 Catch FormatException caused by bad simctl output

37966 Remove ephemeral directories during flutter clean

37994 Remove no-constant-update-2018, the underlying issue has been resolved.

38101 Catch filesystem exception from flutter create

38102 Fix type error hidden by implicit downcasts

38296 use common emulator/device list

38339 [flutter_tool] Flip create language defaults to swift and kotlin

38342 remove bsdiff from BUILD.gn

38353 [flutter_tool] Observatory connection error handling cleanup

38472 [flutter_tool] Fix bug in manifest yaml validation