chore: regenerate README (#643)

This PR was generated using Autosynth. 🌈


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

```
2021-08-24 19:31:28,037 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-vision/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-08-24 19:31:29,318 synthtool [DEBUG] > Wrote metadata to .github/readme/synth.metadata/synth.metadata.

```
</details>

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https://source.cloud.google.com/results/invocations/20d38a6c-7813-4cb6-b933-276bb5e65ce6/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-vision.git",
-        "sha": "c20763641495ce2f9d157d2862a6640c80fb7151"
+        "sha": "a124fb7da9d279e4c4e0c1d5398d904e576fdd7b"
       }
     },
     {

README.md

@@ -42,7 +42,7 @@ If you are using Maven without BOM, add this to your dependencies:
 <dependency>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-vision</artifactId>
-  <version>2.0.3</version>
+  <version>2.0.4</version>
 </dependency>
 
 ```