fix(android): add a missing function in gradle

Author: craftzdog

android/build.gradle

@@ -17,6 +17,10 @@ def getExtOrDefault(name) {
   return rootProject.ext.has(name) ? rootProject.ext.get(name) : project.properties['SQLite2_' + name]
 }
 
+def getExtOrIntegerDefault(name) {
+  return rootProject.ext.has(name) ? rootProject.ext.get(name) : (project.properties['SQLite2_' + name]).toInteger()
+}
+
 android {
   compileSdkVersion getExtOrIntegerDefault('compileSdkVersion')
   buildToolsVersion getExtOrDefault('buildToolsVersion')