Simplify Maven enforcer plugin usage.

PiperOrigin-RevId: 899633115
Change-Id: I4520cc70a53b8bc9528cb956695d742c313808e0

Author: ludoch

applications/guestbook/pom.xml

@@ -32,10 +32,6 @@
     <url>https://github.com/GoogleCloudPlatform/appengine-java-standard/</url>
     <description>A guestbook sample application.</description>
 
-    <prerequisites>
-        <maven>3.6.0</maven>
-    </prerequisites>
-
     <properties>
         <maven.deploy.skip>true</maven.deploy.skip>
         <appengine.target.version>5.0.1-SNAPSHOT</appengine.target.version>
@@ -91,6 +87,10 @@
         <outputDirectory>target/${project.artifactId}-${project.version}/WEB-INF/classes</outputDirectory>
 
         <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-enforcer-plugin</artifactId>
+            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-surefire-plugin</artifactId>

applications/guestbook_jakarta/pom.xml

@@ -32,10 +32,6 @@
     <url>https://github.com/GoogleCloudPlatform/appengine-java-standard/</url>
     <description>A guestbook sample application (Jakarta).</description>
 
-    <prerequisites>
-        <maven>3.6.0</maven>
-    </prerequisites>
-
     <properties>
         <maven.deploy.skip>true</maven.deploy.skip>
         <appengine.target.version>5.0.1-SNAPSHOT</appengine.target.version>
@@ -91,6 +87,10 @@
         <outputDirectory>target/${project.artifactId}-${project.version}/WEB-INF/classes</outputDirectory>
 
         <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-enforcer-plugin</artifactId>
+            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-surefire-plugin</artifactId>

applications/jaxrs/pom.xml

@@ -32,10 +32,6 @@
     <url>https://github.com/GoogleCloudPlatform/appengine-java-standard/</url>
     <description>A jaxrs sample application.</description>
 
-    <prerequisites>
-        <maven>3.6.0</maven>
-    </prerequisites>
-
     <properties>
         <maven.deploy.skip>true</maven.deploy.skip>
         <appengine.target.version>5.0.1-SNAPSHOT</appengine.target.version>
@@ -74,6 +70,10 @@
         <outputDirectory>target/${project.artifactId}-${project.version}/WEB-INF/classes</outputDirectory>
 
         <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-enforcer-plugin</artifactId>
+            </plugin>
             <plugin>
                 <groupId>org.eclipse.jetty.ee8</groupId>
                 <artifactId>jetty-ee8-maven-plugin</artifactId>

applications/pom.xml

@@ -30,6 +30,18 @@
   <properties>
        <maven.deploy.skip>true</maven.deploy.skip>
   </properties>
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-enforcer-plugin</artifactId>
+      </plugin>
+    </plugins>
+    <pluginManagement>
+      <plugins>
+      </plugins>
+    </pluginManagement>
+  </build>
   <modules>
     <module>proberapp</module>
     <module>proberapp_jakarta</module>