chore: modernize post-processing for 12 libraries (#13836)

Remove legacy owlbot.py scripts and migrate configurations to librarian.yaml for the following libraries:
- kms
- logging
- monitoring
- monitoring-dashboards
- network-management
- os-login
- pubsub
- securitycenter
- service-management
- spanner
- tasks
- vision 

For googleapis/librarian#6931

Author: yangyzs

java-kms/README.md

@@ -11,7 +11,6 @@ Java idiomatic client for [Cloud Key Management Service][product-docs].
 
 ## Quickstart
 
-
 If you are using Maven with [BOM][libraries-bom], add this to your pom.xml file:
 
 ```xml
@@ -46,6 +45,14 @@ If you are using Maven without the BOM, add this to your dependencies:
 </dependency>
 ```
 
+If you are using Gradle 5.x or later, add this to your dependencies:
+
+```Groovy
+implementation platform('com.google.cloud:libraries-bom:26.83.0')
+
+implementation 'com.google.cloud:google-cloud-kms'
+```
+
 If you are using Gradle without BOM, add this to your dependencies:
 
 ```Groovy
@@ -71,7 +78,7 @@ The client application making API calls must be granted [authorization scopes][a
 ### Prerequisites
 
 You will need a [Google Cloud Platform Console][developer-console] project with the Cloud Key Management Service [API enabled][enable-api].
-
+You will need to [enable billing][enable-billing] to use Google Cloud Key Management Service.
 [Follow these instructions][create-project] to get your project set up. You will also need to set up the local development environment by
 [installing the Google Cloud Command Line Interface][cloud-cli] and running the following commands in command line:
 `gcloud auth login` and `gcloud config set project [YOUR PROJECT ID]`.
@@ -147,8 +154,6 @@ the individual GitHub repository `github.com/GoogleAPIs/java-SERVICENAME`
 and on [google-cloud-java][g-c-j].
 
 ## Versioning
-
-
 This library follows [Semantic Versioning](http://semver.org/).
 
 
@@ -187,7 +192,7 @@ Java is a registered trademark of Oracle and/or its affiliates.
 [contributing]: https://github.com/googleapis/google-cloud-java/blob/main/CONTRIBUTING.md
 [code-of-conduct]: https://github.com/googleapis/google-cloud-java/blob/main/CODE_OF_CONDUCT.md#contributor-code-of-conduct
 [license]: https://github.com/googleapis/google-cloud-java/blob/main/LICENSE
-
+[enable-billing]: https://cloud.google.com/apis/docs/getting-started#enabling_billing
 [enable-api]: https://console.cloud.google.com/flows/enableapi?apiid=cloudkms.googleapis.com
 [libraries-bom]: https://github.com/GoogleCloudPlatform/cloud-opensource-java/wiki/The-Google-Cloud-Platform-Libraries-BOM
 [shell_img]: https://gstatic.com/cloudssh/images/open-btn.png