Team City Build Failed : diamond operator is not supported in -source 1.6

Question

In the Team City I create an agent build ECS branch, it always failed and throw errors:

/CorsFilter.java:[91,67] diamond operator is not supported in -source 1.6(use -source 7 or higher to enable diamond operator)

The Java version is 1.8.131, not 1.6. I checked information within Team city, 1.6 is not mentioned. I don't know why it is throwing this exception.

CorsFiler.java

private final Collection<String> allowedOrigins = new HashSet<>();

Pom.xml

<build>
  <plugins>
    <plugin>
      <groupId>org.apache.maven.plugins</groupId>
      <artifactId>maven-antrun-plugin</artifactId>
      <inherited>false</inherited>
      <executions>
        <execution>
          <phase>install</phase>
          <configuration>
            <tasks>
              <move
                file="${project.basedir}/target/test.war"
                tofile="${project.basedir}/test.war"
              />
            </tasks>
          </configuration>
          <goals>
            <goal>run</goal>
          </goals>
        </execution>
      </executions>
    </plugin>
  </plugins>
</build>

Hope team city build success.