Which version of AEM are you using @sathyaprakasha2 . In most of the latest version of AEM , google gson bundle should be available in the felix console already. Can you check /system/console/depfinder and search for the archetype you want to install ?
I have 6.5 version and I already have gson in my felix console. PFB the screenshot. You can copy the dependency from here and add it in the pom.xml files under <dependencyManagement><dependencies> section.
In maven-bundle-plugin,<wrapImportPackage>;</wrapImportPackage> would add all your dependencies as resources in the generated jar file and configure the bundle classpath for you. bnd-maven-plugin does not use instructions in the POM. You have to do that in bnd file. in the link provided below will show you an example of -includeresource instruction and how to set your bundle classpath.