deps: bump com.google.cloud.tools:appengine-maven-plugin (#2524)

Bumps [com.google.cloud.tools:appengine-maven-plugin](https://github.com/GoogleCloudPlatform/appengine-plugins) from 2.5.0 to 2.7.0.
- [Release notes](https://github.com/GoogleCloudPlatform/appengine-plugins/releases)
- [Changelog](https://github.com/GoogleCloudPlatform/appengine-plugins/blob/main/CHANGELOG.md)
- [Commits](https://github.com/GoogleCloudPlatform/appengine-plugins/commits/v2.7.0)

---
updated-dependencies:
- dependency-name: com.google.cloud.tools:appengine-maven-plugin
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

spring-cloud-gcp-samples/pom.xml

@@ -25,7 +25,7 @@
 		<checkstyle-rules.version>9.3</checkstyle-rules.version>
 
 		<!-- App engine plugin version, used to deploy sample apps -->
-		<app-engine-maven-plugin.version>2.5.0</app-engine-maven-plugin.version>
+		<app-engine-maven-plugin.version>2.7.0</app-engine-maven-plugin.version>
 
 		<!-- Deploy plugin is skipped for all samples but exists -->
 		<maven-deploy-plugin.version>3.1.1</maven-deploy-plugin.version>