add check header files path properties into main pom

apm-collector/apm-collector-agentstream/src/test/java/org/skywalking/apm/collector/agentstream/TestCheckStyle.java

-package org.skywalking.apm.collector.agentstream;
-
-/**
- * @author pengys5
- */
-public class TestCheckStyle {
-}

checkStyle.xml

@@ -30,7 +30,7 @@
 
     <!-- header -->
     <module name="Header">
-        <property name="headerFile" value="java.header"/>
+        <property name="headerFile" value="${checkstyle.header.file}"/>
     </module>
 
     <module name="RegexpSingleline">

pom.xml

@@ -87,6 +87,7 @@
         <scala.compiler.version>2.11.7</scala.compiler.version>
         <powermock.version>1.6.4</powermock.version>
         <docker.plugin.version>0.4.13</docker.plugin.version>
+        <checkstyle.header.file>java.header</checkstyle.header.file>
     </properties>
 
     <dependencies>