revert pubsub version changes - which will be picked up by version bump script during release

Author: neozwu

google-cloud-clients/google-cloud-pubsub/README.md

@@ -24,16 +24,16 @@ Add this to your pom.xml file
 <dependency>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-pubsub</artifactId>
-  <version>1.30.0</version>
+  <version>0.48.0-beta</version>
 </dependency>
 ```
 If you are using Gradle, add this to your dependencies
 ```Groovy
-compile 'com.google.cloud:google-cloud-pubsub:1.30.0'
+compile 'com.google.cloud:google-cloud-pubsub:0.48.0-beta'
 ```
 If you are using SBT, add this to your dependencies
 ```Scala
-libraryDependencies += "com.google.cloud" % "google-cloud-pubsub" % "1.30.0"
+libraryDependencies += "com.google.cloud" % "google-cloud-pubsub" % "0.48.0-beta"
 ```
 [//]: # ({x-version-update-end})
 

google-cloud-clients/google-cloud-pubsub/pom.xml

@@ -2,7 +2,7 @@
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
   <modelVersion>4.0.0</modelVersion>
   <artifactId>google-cloud-pubsub</artifactId>
-  <version>1.30.1-SNAPSHOT</version><!-- {x-version-update:google-cloud-pubsub:current} -->
+  <version>0.48.1-beta-SNAPSHOT</version><!-- {x-version-update:google-cloud-pubsub:current} -->
   <packaging>jar</packaging>
   <name>Google Cloud Pub/Sub</name>
   <url>https://github.com/GoogleCloudPlatform/google-cloud-java/tree/master/google-cloud-pubsub</url>