chore: use require-hashes option for owlbot docker image (#1592) (#1017)

* chore: use require-hashes option for owlbot docker image

Co-authored-by: Mike Eltsufin <[email protected]>
Source-Link: googleapis/synthtool@d7d1a87
Post-Processor: gcr.io/cloud-devrel-public-resources/owlbot-java:latest@sha256:faab4ce05feb201db2dbbec4eff44b1f132d5e0316f7ba1c25e538516973fae3

Author: gcf-owl-bot[bot]

.github/.OwlBot.lock.yaml

@@ -13,4 +13,4 @@
 # limitations under the License.
 docker:
   image: gcr.io/cloud-devrel-public-resources/owlbot-java:latest
-  digest: sha256:8175681a918181d306d9c370d3262f16b4c724cc73d74111b7d42fc985ca7f93
+  digest: sha256:faab4ce05feb201db2dbbec4eff44b1f132d5e0316f7ba1c25e538516973fae3

README.md

@@ -56,13 +56,13 @@ implementation 'com.google.cloud:google-cloud-dialogflow'
 If you are using Gradle without BOM, add this to your dependencies:
 
 ```Groovy
-implementation 'com.google.cloud:google-cloud-dialogflow:4.8.5'
+implementation 'com.google.cloud:google-cloud-dialogflow:4.8.6'
 ```
 
 If you are using SBT, add this to your dependencies:
 
 ```Scala
-libraryDependencies += "com.google.cloud" % "google-cloud-dialogflow" % "4.8.5"
+libraryDependencies += "com.google.cloud" % "google-cloud-dialogflow" % "4.8.6"
 ```
 
 ## Authentication