web.xml

en el web.xml agregar

 <context-param>
        <param-name>primefaces.THEME</param-name>
        <param-value>admin</param-value>
    </context-param>
    <context-param>
        <param-name>primefaces.FONT_AWESOME</param-name>
        <param-value>true</param-value>
    </context-param>
    <context-param>
        <param-name>primefaces.MOVE_SCRIPTS_TO_BOTTOM</param-name>
        <param-value>true</param-value>
    </context-param>
    <context-param>
        <param-name>com.sun.faces.numberOfLogicalViews</param-name>
        <param-value>6</param-value>
    </context-param>
    <context-param>
        <param-name>com.sun.faces.numberOfViewsInSession</param-name>
        <param-value>6</param-value>
    </context-param>
    <context-param>
        <param-name>org.omnifaces.VIEW_SCOPE_MANAGER_MAX_ACTIVE_VIEW_SCOPES</param-name>
        <param-value>6</param-value>
    </context-param>
    <context-param>
        <param-name>javax.faces.INTERPRET_EMPTY_STRING_SUBMITTED_VALUES_AS_NULL</param-name>
        <param-value>true</param-value>
    </context-param>
   
    
    
    <filter>
        <filter-name>gzipResponseFilter</filter-name>
        <filter-class>org.omnifaces.filter.GzipResponseFilter</filter-class>
        <init-param>
            <description>The threshold size in bytes. Must be a number between 0 and 9999. Defaults to 150.
            </description>
            <param-name>threshold</param-name>
            <param-value>200</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>gzipResponseFilter</filter-name>
        <servlet-name>Faces Servlet</servlet-name>
        <dispatcher>REQUEST</dispatcher>
        <dispatcher>ERROR</dispatcher>
    </filter-mapping>

Quedaría

 <?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
    <context-param>
        <param-name>javax.faces.PROJECT_STAGE</param-name>
        <param-value>Development</param-value>
    </context-param>
    
    <!--
    -->
    <context-param>
        <param-name>primefaces.THEME</param-name>
        <param-value>admin</param-value>
    </context-param>
    <context-param>
        <param-name>primefaces.FONT_AWESOME</param-name>
        <param-value>true</param-value>
    </context-param>
    <context-param>
        <param-name>primefaces.MOVE_SCRIPTS_TO_BOTTOM</param-name>
        <param-value>true</param-value>
    </context-param>
    <context-param>
        <param-name>com.sun.faces.numberOfLogicalViews</param-name>
        <param-value>6</param-value>
    </context-param>
    <context-param>
        <param-name>com.sun.faces.numberOfViewsInSession</param-name>
        <param-value>6</param-value>
    </context-param>
    <context-param>
        <param-name>org.omnifaces.VIEW_SCOPE_MANAGER_MAX_ACTIVE_VIEW_SCOPES</param-name>
        <param-value>6</param-value>
    </context-param>
    <context-param>
        <param-name>javax.faces.INTERPRET_EMPTY_STRING_SUBMITTED_VALUES_AS_NULL</param-name>
        <param-value>true</param-value>
    </context-param>
<!--    <welcome-file-list>
        <welcome-file>index.html</welcome-file>
    </welcome-file-list>-->
<!--    <servlet>
        <servlet-name>Faces Servlet</servlet-name>
        <servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>-->
    
    <filter>
        <filter-name>gzipResponseFilter</filter-name>
        <filter-class>org.omnifaces.filter.GzipResponseFilter</filter-class>
        <init-param>
            <description>The threshold size in bytes. Must be a number between 0 and 9999. Defaults to 150.
            </description>
            <param-name>threshold</param-name>
            <param-value>200</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>gzipResponseFilter</filter-name>
        <servlet-name>Faces Servlet</servlet-name>
        <dispatcher>REQUEST</dispatcher>
        <dispatcher>ERROR</dispatcher>
    </filter-mapping>
    <!--
    -->
    
    <servlet>
        <servlet-name>Faces Servlet</servlet-name>
        <servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>Faces Servlet</servlet-name>
        <url-pattern>/faces/*</url-pattern>
    </servlet-mapping>
    <session-config>
        <session-timeout>
            30
        </session-timeout>
    </session-config>
    <welcome-file-list>
        <welcome-file>faces/index.xhtml</welcome-file>
    </welcome-file-list>
</web-app>