feat: promote to 1.0.0 (#32)

* feat: promote to 1.0.0

Release-As: 1.0.0

* 🦉 Updates from OwlBot

See https://github.com/googleapis/repo-automation-bots/blob/master/packages/owl-bot/README.md

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: Neenu1995

.repo-metadata.json

@@ -4,7 +4,7 @@
   "product_documentation": "https://cloud.google.com/network-intelligence-center/docs/connectivity-tests/reference/networkmanagement/rest/",
   "api_description": "provides a collection of network performance monitoring and diagnostic capabilities.",
   "client_documentation": "https://googleapis.dev/java/google-cloud-network-management/latest/index.html",
-  "release_level": "beta",
+  "release_level": "ga",
   "transport": "grpc",
   "language": "java",
   "repo": "googleapis/java-network-management",
@@ -13,4 +13,4 @@
   "api_id": "networkmanagement.googleapis.com",
   "library_type": "GAPIC_AUTO",
   "requires_billing": true
-}
+}

README.md

@@ -8,9 +8,6 @@ Java idiomatic client for [Network Management API][product-docs].
 - [Product Documentation][product-docs]
 - [Client Library Documentation][javadocs]
 
-> Note: This client is a work-in-progress, and may occasionally
-> make backwards-incompatible changes.
-
 
 ## Quickstart
 
@@ -132,9 +129,6 @@ and on [google-cloud-java][g-c-j].
 This library follows [Semantic Versioning](http://semver.org/).
 
 
-It is currently in major version zero (``0.y.z``), which means that anything may change at any time
-and the public API should not be considered stable.
-
 
 ## Contributing
 
@@ -176,7 +170,7 @@ Java is a registered trademark of Oracle and/or its affiliates.
 [kokoro-badge-link-4]: http://storage.googleapis.com/cloud-devrel-public/java/badges/java-network-management/java8-win.html
 [kokoro-badge-image-5]: http://storage.googleapis.com/cloud-devrel-public/java/badges/java-network-management/java11.svg
 [kokoro-badge-link-5]: http://storage.googleapis.com/cloud-devrel-public/java/badges/java-network-management/java11.html
-[stability-image]: https://img.shields.io/badge/stability-beta-yellow
+[stability-image]: https://img.shields.io/badge/stability-ga-green
 [maven-version-image]: https://img.shields.io/maven-central/v/com.google.cloud/google-cloud-network-management.svg
 [maven-version-link]: https://search.maven.org/search?q=g:com.google.cloud%20AND%20a:google-cloud-network-management&core=gav
 [authentication]: https://github.com/googleapis/google-cloud-java#authentication