chore: regenerate README (#578)

This PR was generated using Autosynth. 🌈


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

```
2021-07-29 23:23:04,757 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-aiplatform/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-07-29 23:23:06,019 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/1e469d7b-c5b8-4215-9b4b-66f58824d2af/targets

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

@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-aiplatform.git",
-        "sha": "e8d8712abbd9e471f00a84574a58e8e80ef43854"
+        "sha": "05f23b58841550263778475ce89211fd25f1d624"
       }
     },
     {