chore: regenerate README (#1012)

This PR was generated using Autosynth. 🌈


<details><summary>Log from Synthtool</summary>

```
2021-04-15 21:13:41,184 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-bigquerystorage/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-04-15 21:13:42,568 synthtool [DEBUG] > Wrote metadata to .github/readme/synth.metadata/synth.metadata.

```
</details>

Full log will be available here:
https://source.cloud.google.com/results/invocations/96bbeb18-f422-4498-93cb-432438c3e8ad/targets

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.github/readme/synth.metadata/synth.metadata

@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-bigquerystorage.git",
-        "sha": "08ee25322e259b93f2662402c8580e68652053eb"
+        "sha": "cc243d97a14df3c94133b0705d6e5d5ef92a8286"
       }
     },
     {

README.md

@@ -17,7 +17,7 @@ If you are using Maven with [BOM][libraries-bom], add this to your pom.xml file
     <dependency>
       <groupId>com.google.cloud</groupId>
       <artifactId>libraries-bom</artifactId>
-      <version>20.0.0</version>
+      <version>20.1.0</version>
       <type>pom</type>
       <scope>import</scope>
     </dependency>
@@ -51,12 +51,12 @@ compile 'com.google.cloud:google-cloud-bigquerystorage'
 ```
 If you are using Gradle without BOM, add this to your dependencies
 ```Groovy
-compile 'com.google.cloud:google-cloud-bigquerystorage:1.18.1'
+compile 'com.google.cloud:google-cloud-bigquerystorage:1.19.0'
 ```
 
 If you are using SBT, add this to your dependencies
 ```Scala
-libraryDependencies += "com.google.cloud" % "google-cloud-bigquerystorage" % "1.18.1"
+libraryDependencies += "com.google.cloud" % "google-cloud-bigquerystorage" % "1.19.0"
 ```
 
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