feat(play-install-referrer): add plugin (#3718)

* Added plugin for cordova-in-app-update android

* feat(play-install-referrer) Plugin wrapper for Ionic

* Updated play-install-referrer wrapper

Author: Nandan B N

src/@ionic-native/plugins/play-install-referrer/index.ts

@@ -0,0 +1,17 @@
+import { Injectable } from '@angular/core';
+import { Plugin, Cordova, IonicNativePlugin } from '@ionic-native/core';
+
+@Plugin({
+  pluginName: 'PlayInstallReferrer',
+  plugin: 'cordova-plugin-play-installreferrer',
+  pluginRef: 'installReferrer',
+  repo: 'https://github.com/swayangjit/cordova-plugin-play-installreferrer',
+  platforms: ['Android'],
+})
+@Injectable()
+export class PlayInstallReferrer extends IonicNativePlugin {
+  @Cordova()
+  getReferrer(): Promise<any> {
+    return;
+  }
+}