[fix] target device selector updates

[pq]

In #8853, users are reporting an exception in Android Studio thanks to excessive toolbar updates. This is caused by the Flutter plugin triggering frequent global toolbar updates via a call to ActivityTracker.getInstance().inc() whenever the device or emulator lists change.

The Fix. To reduce update frequency, this change makes the updates targeted, removing the (global)ActivityTracker.getInstance().inc() calls from DeviceSelectorAction.updateActions() and DeviceService.refreshDeviceDaemon(), invoking a newly extracted updateComponent method in DeviceSelectorAction instead. This ensures that the Flutter device selector UI still updates immediately when devices are connected or disconnected, but without forcing a global re-query of all actions on the toolbar.

Verification. Verified manually and io.flutter.actions.DeviceSelectorActionTest still passes.

Fixes #8853

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[gemini-code-assist]

Code Review

This pull request refactors the device selection logic by extracting UI update logic into a dedicated updateComponent method and removing manual ActivityTracker increments. The review identified critical threading violations where UI-related operations in updateComponent are executed on a background thread instead of the Event Dispatch Thread (EDT). Additionally, a redundant call to updateComponent was found that should be removed to avoid unnecessary processing.