Fix gradle example

Gradle jib plugin (`com.google.cloud.tools.jib`) needs to be updated to 3.3.2 to eliminate the following error:

```text
com.google.cloud.tools.jib.plugins.common.BuildStepsExecutionException: Unknown mediaType: application/vnd.oci.image.index.v1+json
```

This is currently updated in the `update-build.gradle` branch of the `example-gradle` repository: https://github.com/buildsec/example-gradle/tree/update-build.gradle

Signed-off-by: Brad Beck <bradley.beck@gmail.com>

examples/gradle-pipeline/gradle-pipeline-run.sh

@@ -12,7 +12,7 @@ mkdir /tmp/example-gradle
 cd /tmp/example-gradle
 git clone https://frsca:demo1234@gitea-http:3000/frsca/example-gradle .
 git commit -m 'Trigger Build' --allow-empty
-git push origin master
+git push
 cd -
 rm -rf /tmp/example-gradle
 EOF

platform/50-example-mirror.sh

@@ -58,7 +58,7 @@ EOF
 
 gitea_copy_repo https://github.com/buildsec/example-buildpacks example-buildpacks main
 gitea_copy_repo https://github.com/buildsec/example-golang example-golang master
-gitea_copy_repo https://github.com/buildsec/example-gradle example-gradle master
+gitea_copy_repo https://github.com/buildsec/example-gradle example-gradle update-build.gradle
 gitea_copy_repo https://github.com/buildsec/example-ibm-tutorial example-ibm-tutorial master
 gitea_copy_repo https://github.com/buildsec/example-maven example-maven master
 gitea_copy_repo https://github.com/buildsec/example-sample-pipeline example-sample-pipeline wolfi