Watchdog should start with WAITING state, and only switch to `idle` if
auto flow control was disabled. Before the fix, when auto flow control
was enabled, we wait for server to return a response without calling
`onRequest()` and watchdog would report the timeout exception because of
idle timeout, which is incorrect and causes confusion.

Before submitting your PR, there are a few things you can do to make
sure it goes smoothly:

- [ ] Make sure to open an issue as a
[bug/issue](https://github.com/googleapis/gapic-generator-java/issues/new/choose)
before writing your code! That way we can discuss the change, evaluate
designs, and agree on the general idea
- [ ] Ensure the tests and linter pass
- [ ] Code coverage does not decrease (if any source code was changed)
- [ ] Appropriate docs were updated (if necessary)

Fixes #2498 ☕️

---------

Co-authored-by: Igor Bernstein <igorbernstein@google.com>
Co-authored-by: Lawrence Qiu <lawrenceqiu@google.com>

Watchdog should start with WAITING state, and only switch to `idle` if
auto flow control was disabled. Before the fix, when auto flow control
was enabled, we wait for server to return a response without calling
`onRequest()` and watchdog would report the timeout exception because of
idle timeout, which is incorrect and causes confusion.

Before submitting your PR, there are a few things you can do to make
sure it goes smoothly:

- [ ] Make sure to open an issue as a
[bug/issue](https://github.com/googleapis/gapic-generator-java/issues/new/choose)
before writing your code! That way we can discuss the change, evaluate
designs, and agree on the general idea
- [ ] Ensure the tests and linter pass
- [ ] Code coverage does not decrease (if any source code was changed)
- [ ] Appropriate docs were updated (if necessary)

Fixes #2498 ☕️

---------

Co-authored-by: Igor Bernstein <igorbernstein@google.com>
Co-authored-by: Lawrence Qiu <lawrenceqiu@google.com>

🤖 I have created a release *beep* *boop*
---


<details><summary>2.36.0</summary>

##
[2.36.0](v2.35.0...v2.36.0)
(2024-02-29)


### Features

* check library_name is unique among libraries
([#2490](#2490))
([8123f0b](8123f0b))


### Bug Fixes

* cleanup @BetaApi from Resource Name Builder Methods
([#2450](#2450))
([6e8d098](6e8d098)),
closes
[#2099](#2099)
* Fix watchdog to start with WAITING state
([#2468](#2468))
([dedc40f](dedc40f))
* ignore comment in BUILD
([#2492](#2492))
([6ca20e5](6ca20e5))
* remove @BetaApi from ApiFutures and ApiService
([#2454](#2454))
([f59e717](f59e717)),
closes
[#2098](#2098)


### Dependencies

* grandfathering the dependencies for java-pubsublite and java-bigquery
([#2504](#2504))
([9ceab23](9ceab23))
* update dependency gradle to v7.6.4
([#2474](#2474))
([607dc59](607dc59))
* update dependency org.graalvm.sdk:graal-sdk to v22.3.5
([#2475](#2475))
([2de487b](2de487b))
* update grpc dependencies to v1.62.2
([#2506](#2506))
([f438603](f438603))


### Documentation

* Add contribution guidelines.
([#2045](#2045))
([9939b43](9939b43))
</details>

---
This PR was generated with [Release
Please](https://github.com/googleapis/release-please). See
[documentation](https://github.com/googleapis/release-please#release-please).

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>