Restructure ProtoBuf & gRPC project structure

- pom.xml {protobuf, grpc}-dependencies to consolidte
  plugin configuration, dependency version property

- {protobuf, grpc}: ONOS App to load required feature/bundle

- all other atrifacts: Apps using protobuf/grpc inherit
  ~-dependencies above to reduce copy & paste configurations and
  dependency versions.

Change-Id: Ied90aff78ffddac6228d46e85e01d035eec37bee
diff --git a/incubator/grpc/pom.xml b/incubator/grpc/pom.xml
index aee92887..6a8c07f 100644
--- a/incubator/grpc/pom.xml
+++ b/incubator/grpc/pom.xml
@@ -19,9 +19,10 @@
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <parent>
-        <artifactId>onos-incubator</artifactId>
+        <artifactId>onos-incubator-grpc-dependencies</artifactId>
         <groupId>org.onosproject</groupId>
         <version>1.9.0-SNAPSHOT</version>
+        <relativePath>../grpc-dependencies/pom.xml</relativePath>
     </parent>
     <modelVersion>4.0.0</modelVersion>
 
@@ -30,13 +31,7 @@
 
     <properties>
         <onos.app.name>org.onosproject.incubator.grpc</onos.app.name>
-        <onos.app.title>gRPC dependency package</onos.app.title>
-        <protobuf.version>3.0.0</protobuf.version>
-        <grpc.version>1.0.0</grpc.version>
-        <grpc.package.version>1.0.0</grpc.package.version>
-        <grpc.netty.version>4.1.3.Final</grpc.netty.version>
-        <grpc.netty.package.version>4.1.3</grpc.netty.package.version>
-        <google.auth.version>0.4.0</google.auth.version>
+        <onos.app.title>gRPC dependency App</onos.app.title>
     </properties>
 
     <!-- gRPC requires more recent version of netty -->
@@ -128,5 +123,4 @@
         </plugins>
     </build>
 
-
 </project>