CB-3445: android: Copy Gradle wrapper from Android SDK rather than bundling a JAR

bin/lib/check_reqs.js

@@ -24,6 +24,7 @@ var shell = require('shelljs'),
     Q     = require('q'),
     path  = require('path'),
     fs    = require('fs'),
+    which = require('which'),
     ROOT  = path.join(__dirname, '..', '..');
 
 // Get valid target from framework/project.properties
@@ -40,6 +41,23 @@ module.exports.get_target = function() {
     }
 }
 
+// Returns a promise.
+module.exports.sdk_dir = function() {
+    var d = Q.defer();
+    which('android', function(err, path) {
+        if (err) {
+            d.reject(new Error('ERROR: Cannot find Android SDK. android command not found.'));
+        } else {
+            var toolsDir = path.substring(0, path.lastIndexOf('/'));
+            if (toolsDir.substring(toolsDir.length-6) != "/tools") {
+                d.reject(new Error('ERROR: Cannot find Android SDK. android command not found in tools dir.'));
+            }
+            d.resolve(toolsDir.substring(0, toolsDir.length-6));
+        }
+    });
+    return d.promise;
+};
+
 // Returns a promise.
 module.exports.check_ant = function() {
     var d = Q.defer();