Support Gradle projects in lint-java

### TL;DR

I tried configuring lint-java for https://github.com/googleads/data-manager-java, which uses Gradle, but it fails because there's no `pom.xml` file for a Gradle project:

```
Run abcxyz/actions/.github/actions/lint-java@main
Run graalvm/setup-graalvm@01ed653ac833fe80569f1ef9f25585ba2811baab

/usr/bin/tar xz --warning=no-unknown-keyword --overwrite -C /home/runner/work/_temp/9534f092-6ac3-42dc-a25c-22dbd62c221e -f /home/runner/work/_temp/c40e806f-8c0a-4ccc-aed0-5ad50fc04549
Adding graalvm-community-jdk-21.0.2_linux-x64_bin 21.0.2 to tool-cache ...
Error: No file in /home/runner/work/data-manager-java/data-manager-java matched to [**/pom.xml], make sure you have checked out the target repository
```

### Detailed design

```markdown

```

### Alternatives considered

```markdown
I could modify my Gradle build to generate POMs, but that seems like an unnecessary burden to place on every project using the action.
```

### Additional information

_No response_