docs(sample): Use Java 8 for native image sample (#893)

* fix(java): Use Java 8 for native image sample * 🦉 Updates from OwlBot post-processor See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md * 🦉 Updates from OwlBot post-processor See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: mpeddada1

README.md

@@ -56,13 +56,13 @@ implementation 'com.google.cloud:google-cloud-firestore'
 If you are using Gradle without BOM, add this to your dependencies
 
 ```Groovy
-implementation 'com.google.cloud:google-cloud-firestore:3.0.13'
+implementation 'com.google.cloud:google-cloud-firestore:3.0.14'
 ```
 
 If you are using SBT, add this to your dependencies
 
 ```Scala
-libraryDependencies += "com.google.cloud" % "google-cloud-firestore" % "3.0.13"
+libraryDependencies += "com.google.cloud" % "google-cloud-firestore" % "3.0.14"
 ```
 
 ## Authentication

samples/native-image-sample/pom.xml

@@ -20,8 +20,9 @@ http://maven.apache.org/xsd/maven-4.0.0.xsd">
  </parent>
 
  <properties>
- <maven.compiler.target>11</maven.compiler.target>
- <maven.compiler.source>11</maven.compiler.source>
+ <!-- Java 8 because the Kokoro Sample test uses that Java version -->
+ <maven.compiler.target>1.8</maven.compiler.target>
+ <maven.compiler.source>1.8</maven.compiler.source>
  <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>
 
@@ -65,8 +66,7 @@ http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <configuration>
  <archive>
  <manifest>
- <mainClass>com.example.firestore.NativeImageFirestoreSample
- </mainClass>
+ <mainClass>com.example.firestore.NativeImageFirestoreSample</mainClass>
  </manifest>
  </archive>
  </configuration>
@@ -118,8 +118,7 @@ http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <version>0.9.10</version>
  <extensions>true</extensions>
  <configuration>
- <mainClass>com.example.firestore.NativeImageFirestoreSample
- </mainClass>
+ <mainClass>com.example.firestore.NativeImageFirestoreSample</mainClass>
  <buildArgs>
  <buildArg>--no-fallback</buildArg>
  <buildArg>--no-server</buildArg>