This reverts commit adc9dde3ba.
- Fixed issue where `FallbackDiscovery` would hold on to a `VmService` when launching on iOS devices, causing DDS to fail to start
- Fixed `flutter drive` case where DDS is already running in another flutter_tools instance
Tracing tests
The tests in this folder must be run with flutter test --enable-vmservice,
since they test that trace data is written to the timeline by connecting to
the observatory.
These tests will fail if run without this flag.