deps: update dependency com.google.code.gson:gson to v2.8.9 (#1492)
deps: update dependency com.google.code.gson:gson to v2.8.9 (#1492)

[![WhiteSource Renovate](https://app.renovatebot.com/images/banner.svg)](https://renovatebot.com)

This PR contains the following updates:

| Package | Change | Age | Adoption | Passing | Confidence |
|---|---|---|---|---|---|
| [com.google.code.gson:gson](https://togithub.com/google/gson) | `2.8.8` -> `2.8.9` | [![age](https://badges.renovateapi.com/packages/maven/com.google.code.gson:gson/2.8.9/age-slim)](https://docs.renovatebot.com/merge-confidence/) | [![adoption](https://badges.renovateapi.com/packages/maven/com.google.code.gson:gson/2.8.9/adoption-slim)](https://docs.renovatebot.com/merge-confidence/) | [![passing](https://badges.renovateapi.com/packages/maven/com.google.code.gson:gson/2.8.9/compatibility-slim/2.8.8)](https://docs.renovatebot.com/merge-confidence/) | [![confidence](https://badges.renovateapi.com/packages/maven/com.google.code.gson:gson/2.8.9/confidence-slim/2.8.8)](https://docs.renovatebot.com/merge-confidence/) |

---

### Release Notes

<details>
<summary>google/gson</summary>

### [`v2.8.9`](https://togithub.com/google/gson/blob/master/CHANGELOG.md#Version-289)

-   Make OSGi bundle's dependency on `sun.misc` optional ([#&#8203;1993](https://togithub.com/google/gson/issues/1993)).
-   Deprecate `Gson.excluder()` exposing internal `Excluder` class ([#&#8203;1986](https://togithub.com/google/gson/issues/1986)).
-   Prevent Java deserialization of internal classes ([#&#8203;1991](https://togithub.com/google/gson/issues/1991)).
-   Improve number strategy implementation ([#&#8203;1987](https://togithub.com/google/gson/issues/1987)).
-   Fix LongSerializationPolicy null handling being inconsistent with Gson ([#&#8203;1990](https://togithub.com/google/gson/issues/1990)).
-   Support arbitrary Number implementation for Object and Number deserialization ([#&#8203;1290](https://togithub.com/google/gson/issues/1290)).
-   Bump proguard-maven-plugin from 2.4.0 to 2.5.1 ([#&#8203;1980](https://togithub.com/google/gson/issues/1980)).
-   Don't exclude static local classes ([#&#8203;1969](https://togithub.com/google/gson/issues/1969)).
-   Fix `RuntimeTypeAdapterFactory` depending on internal `Streams` class ([#&#8203;1959](https://togithub.com/google/gson/issues/1959)).
-   Improve Maven build ([#&#8203;1964](https://togithub.com/google/gson/issues/1964)).
-   Make dependency on `java.sql` optional ([#&#8203;1707](https://togithub.com/google/gson/issues/1707)).

</details>

---

### Configuration

📅 **Schedule**: At any time (no schedule defined).

🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied.

♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 **Ignore**: Close this PR and you won't be reminded about this update again.

---

 - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, click this checkbox.

---

This PR has been generated by [WhiteSource Renovate](https://renovate.whitesourcesoftware.com). View repository job log [here](https://app.renovatebot.com/dashboard#github/googleapis/google-http-java-client).
googleapis/google-http-java-client,googleapis/google-http-java-client,googleapis/google-http-java-client,googleapis/google-http-java-client