Adding more examples to apex-pdp

- Adding more examples (DecisionMaker, Periodic & ONAPvCPE) to apex-pdp.
- Fixed CORS issue in plugin-event-carrier-restserver module.
Added a ContainerResponseFilter to intercept every request/response coming to
REST server and add the required headers to support CORS.

Change-Id: Ic3e36c683f2a78992ce1417d2c00233b34066f2f
Issue-ID: POLICY-861
Signed-off-by: ramverma <ram.krishna.verma@ericsson.com>
diff --git a/examples/pom.xml b/examples/pom.xml
index 3d0f969..d31c9ff 100644
--- a/examples/pom.xml
+++ b/examples/pom.xml
@@ -39,5 +39,8 @@
         <module>aadm</module>
         <module>adaptive</module>
         <module>pcvs</module>
+        <module>examples-decisionmaker</module>
+        <module>examples-periodic</module>
+        <module>examples-onap-vcpe</module>
     </modules>
 </project>
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