Replace `npm run get-version` with JSON parser gradle function (#849)

* Replace npm run get-version with JSON parser from groovy

react-native/android/publish_android_template

@@ -66,9 +66,17 @@ String getAppId () {
 
 apply from: 'analytics.gradle'
 
+import groovy.json.JsonSlurper
+
+def getNpmVersion() {
+    def inputFile = new File(buildscript.sourceFile.getParent() + "/../package.json")
+    def packageJson = new JsonSlurper().parseText(inputFile.text)
+    return packageJson["version"]
+}
+
 task send(type: SendAnalyticsTask) {
     applicationId = getAppId()
-    version = "npm --silent run get-version".execute(null, projectDir).text.trim()
+    version = getNpmVersion().trim()
 }
 
 preBuild.dependsOn send