chore: regenerate README (#1451)

This PR was generated using Autosynth. 🌈


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

```
2021-07-15 17:40:24,538 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-bigquery/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-07-15 17:40:26,878 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/5fef9a31-e50d-446f-9f08-89e25341cfe1/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-bigquery.git",
-        "sha": "44d97953febac11c9167efe6781c779f486355d0"
+        "sha": "1649761866b8a81e6ff6f77a5040c0f54b49720a"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "959d4f81f2d1397297ebda90212df92aa0ef3a6a"
+        "sha": "4124d245133c0f740ac5e6fa2e7daeba327f1297"
       }
     }
   ]

README.md

@@ -40,7 +40,7 @@ If you are using Maven without BOM, add this to your dependencies:
 <dependency>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-bigquery</artifactId>
-  <version>1.136.0</version>
+  <version>1.137.0</version>
 </dependency>
 
 ```
@@ -53,12 +53,12 @@ compile 'com.google.cloud:google-cloud-bigquery'
 ```
 If you are using Gradle without BOM, add this to your dependencies
 ```Groovy
-compile 'com.google.cloud:google-cloud-bigquery:1.136.0'
+compile 'com.google.cloud:google-cloud-bigquery:1.137.0'
 ```
 
 If you are using SBT, add this to your dependencies
 ```Scala
-libraryDependencies += "com.google.cloud" % "google-cloud-bigquery" % "1.136.0"
+libraryDependencies += "com.google.cloud" % "google-cloud-bigquery" % "1.137.0"
 ```
 
 ## Authentication