deps: update dependency com.google.api.grpc:proto-google-cloud-pubsublite-v1 to v0.15.0 (#189)

Author: renovate-bot

pom.xml

@@ -48,7 +48,7 @@
     <dependency>
       <groupId>com.google.api.grpc</groupId>
       <artifactId>proto-google-cloud-pubsublite-v1</artifactId>
-      <version>0.14.2</version>
+      <version>0.15.0</version>
     </dependency>
     <dependency>
       <groupId>com.google.guava</groupId>