chore: regenerate README (googleapis#545)

This PR was generated using Autosynth. 🌈


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

```
2021-07-09 14:45:47,820 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-resourcemanager/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-07-09 14:45:49,157 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/af599e6b-6945-4f51-b0c0-7ef0da6112c3/targets

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

java-resourcemanager/.github/readme/synth.metadata/synth.metadata

@@ -4,14 +4,14 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-resourcemanager.git",
-        "sha": "ef8c486f9557873c9ec27b72f15c7e8f34a1dfde"
+        "sha": "265945b320dcf1284696a58d6c27e0a1f12d5069"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "39652e3948f455fd0b77535a0145eeec561a3706"
+        "sha": "09c59c20a4bf0daed1665af59035ff240fe356df"
       }
     }
   ]

java-resourcemanager/README.md

@@ -20,7 +20,7 @@ If you are using Maven with [BOM][libraries-bom], add this to your pom.xml file
     <dependency>
       <groupId>com.google.cloud</groupId>
       <artifactId>libraries-bom</artifactId>
-      <version>20.7.0</version>
+      <version>20.8.0</version>
       <type>pom</type>
       <scope>import</scope>
     </dependency>
@@ -48,7 +48,7 @@ If you are using Maven without BOM, add this to your dependencies:
 
 If you are using Gradle 5.x or later, add this to your dependencies
 ```Groovy
-implementation platform('com.google.cloud:libraries-bom:20.7.0')
+implementation platform('com.google.cloud:libraries-bom:20.8.0')
 
 compile 'com.google.cloud:google-cloud-resourcemanager'
 ```