chore: regenerate README (#262)

This PR was generated using Autosynth. 🌈


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

```
2021-04-12 15:33:44,232 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-mediatranslation/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-04-12 15:33:45,478 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/2283777f-a37e-4249-a820-9355ffef084f/targets

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

@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-mediatranslation.git",
-        "sha": "1e98154a9b3abb57811baeadc5fccb79db511e4f"
+        "sha": "b4176e86b082a891498c8b39e3ef7712a41e2dfd"
       }
     },
     {

README.md

@@ -20,7 +20,7 @@ If you are using Maven, add this to your pom.xml file:
 <dependency>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-mediatranslation</artifactId>
-  <version>0.3.0</version>
+  <version>0.3.1</version>
 </dependency>
 
 ```