deps: update gax.version to v2.19.4 (#875)

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This PR contains the following updates:

| Package | Change | Age | Adoption | Passing | Confidence |
|---|---|---|---|---|---|
| [com.google.api:gax-grpc](https://togithub.com/googleapis/gax-java) | `2.19.2` -> `2.19.4` | [![age](https://badges.renovateapi.com/packages/maven/com.google.api:gax-grpc/2.19.4/age-slim)](https://docs.renovatebot.com/merge-confidence/) | [![adoption](https://badges.renovateapi.com/packages/maven/com.google.api:gax-grpc/2.19.4/adoption-slim)](https://docs.renovatebot.com/merge-confidence/) | [![passing](https://badges.renovateapi.com/packages/maven/com.google.api:gax-grpc/2.19.4/compatibility-slim/2.19.2)](https://docs.renovatebot.com/merge-confidence/) | [![confidence](https://badges.renovateapi.com/packages/maven/com.google.api:gax-grpc/2.19.4/confidence-slim/2.19.2)](https://docs.renovatebot.com/merge-confidence/) |
| [com.google.api:gax-bom](https://togithub.com/googleapis/gax-java) | `2.19.2` -> `2.19.4` | [![age](https://badges.renovateapi.com/packages/maven/com.google.api:gax-bom/2.19.4/age-slim)](https://docs.renovatebot.com/merge-confidence/) | [![adoption](https://badges.renovateapi.com/packages/maven/com.google.api:gax-bom/2.19.4/adoption-slim)](https://docs.renovatebot.com/merge-confidence/) | [![passing](https://badges.renovateapi.com/packages/maven/com.google.api:gax-bom/2.19.4/compatibility-slim/2.19.2)](https://docs.renovatebot.com/merge-confidence/) | [![confidence](https://badges.renovateapi.com/packages/maven/com.google.api:gax-bom/2.19.4/confidence-slim/2.19.2)](https://docs.renovatebot.com/merge-confidence/) |

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### Release Notes

<details>
<summary>googleapis/gax-java</summary>

### [`v2.19.4`](https://togithub.com/googleapis/gax-java/blob/HEAD/CHANGELOG.md#&#8203;2194-httpsgithubcomgoogleapisgax-javacomparev2193v2194-2022-10-19)

[Compare Source](https://togithub.com/googleapis/gax-java/compare/v2.19.2...v2.19.4)

##### Bug Fixes

-   Scope the throttling metric to exclude element size calculation ([#&#8203;1835](https://togithub.com/googleapis/gax-java/issues/1835)) ([0287f83](https://togithub.com/googleapis/gax-java/commit/0287f83f9cabbb9dff6cb7e8ea3068ccc1ab12d9))

</details>

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java-shared-dependencies/first-party-dependencies/pom.xml

@@ -56,7 +56,7 @@
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <site.installationModule>${project.artifactId}</site.installationModule>
     <grpc.version>1.50.1</grpc.version>
-    <gax.version>2.19.2</gax.version>
+    <gax.version>2.19.4</gax.version>
     <grpc-gcp.version>1.3.0</grpc-gcp.version>
     <gson.version>2.9.1</gson.version>
     <guava.version>31.1-jre</guava.version>