chore: regenerate README (#450)

This PR was generated using Autosynth. 🌈


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

```
2021-03-01 17:32:47,868 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-dlp/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-03-01 17:32:49,549 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/44f9b49c-b0e5-47f3-90e0-2a9e6b5a398a/targets

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Author: yoshi-automation

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

@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-dlp.git",
-        "sha": "053fb9727276d95ffc31ed7da257ab0a432c7cc7"
+        "sha": "a1364b34da45d59212fd00c6c8fc17ba0f17ee8d"
       }
     },
     {

README.md

@@ -52,12 +52,12 @@ compile 'com.google.cloud:google-cloud-dlp'
 ```
 If you are using Gradle without BOM, add this to your dependencies
 ```Groovy
-compile 'com.google.cloud:google-cloud-dlp:2.2.8'
+compile 'com.google.cloud:google-cloud-dlp:2.2.9'
 ```
 
 If you are using SBT, add this to your dependencies
 ```Scala
-libraryDependencies += "com.google.cloud" % "google-cloud-dlp" % "2.2.8"
+libraryDependencies += "com.google.cloud" % "google-cloud-dlp" % "2.2.9"
 ```
 
 ## Authentication