[flutter_tool] Make Device.dispose() abstract

[zanderso]

Description

We were failing to unforward ports for Android. The resident runner is calling Device.dispose() in the correct places, but AndroidDevice was inheriting a no-op dispose() method from the Device base class. This PR removes the no-op dispose from the Device base class (and a couple others). This requires implementers of Device to provide an implementation that makes sense. On Android, dispose() now unforwards ports.

Related Issues

Fixes #45948

Tests

I added the following tests:

Added a test to resident_runner_test.dart that ensures that the resident runner is calling dispose() on devices. Added tests to platform specific device tests that calling dispose() on the device results in a call to dispose() on the devices' port forwarders, where appropriate.

Breaking Change

Does your PR require Flutter developers to manually update their apps to accommodate your change?

• No, this is not a breaking change.

[jonahwilliams]

This will likely require a manual update in google3 that should be safe to land first.

[jonahwilliams]

Does this change conflict or allow simplification of the port forwarding in attach? https://github.com/flutter/flutter/blob/master/packages/flutter_tools/lib/src/commands/attach.dart#L331

[jonahwilliams]

LGTM

[blasten]

I filed #46114 to keep track of the flutter attach clean up.

[blasten]

Thanks!