chore: regenerate README (#521)

This PR was generated using Autosynth. 🌈


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

```
2021-05-14 02:14:42,514 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-dlp/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-05-14 02:14:43,880 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/513c20cf-dad3-4e3b-9bf4-9fd01abdbdd1/targets

- [ ] To automatically regenerate this PR, check this box. (May take up to 24 hours.)

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

@@ -4,14 +4,14 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-dlp.git",
-        "sha": "d25949b55750456b1f6d88c94e94b74cccad00d3"
+        "sha": "783ee11598cc197b2ab6a03cf31cf5e1575cf611"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "bd8281a06cc7f84906e04d4843c1d3d386a980cd"
+        "sha": "4f4b1b9b8d8b52f1e9e4a76165896debce5ab7f1"
       }
     }
   ]

README.md

@@ -39,7 +39,7 @@ If you are using Maven without BOM, add this to your dependencies:
 <dependency>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-dlp</artifactId>
-  <version>2.3.2</version>
+  <version>2.3.3</version>
 </dependency>
 
 ```