Adds support for localized push notification in push payload (#4129)

* Adds support for localized push data keys

- passign alert-[lang|locale] or title-[lang|locale] will inject the
  proper locale on the push body based on the installation

* Better handling of the default cases

* Updates changelog

* nits

* nits

spec/PushController.spec.js

@@ -847,7 +847,7 @@ describe('PushController', () => {
     });
   });
 
-  it('should mark the _PushStatus as succeeded when audience has no deviceToken', (done) => {
+  it('should mark the _PushStatus as failed when audience has no deviceToken', (done) => {
     var auth = {
       isMaster: true
     }
@@ -913,4 +913,70 @@ describe('PushController', () => {
       done();
     });
   });
+
+  it('should support localized payload data', (done) => {
+    var payload = {data: {
+      alert: 'Hello!',
+      'alert-fr': 'Bonjour',
+      'alert-es': 'Ola'
+    }}
+
+    var pushAdapter = {
+      send: function(body, installations) {
+        return successfulTransmissions(body, installations);
+      },
+      getValidPushTypes: function() {
+        return ["ios"];
+      }
+    }
+
+    var config = new Config(Parse.applicationId);
+    var auth = {
+      isMaster: true
+    }
+
+    const where = {
+      'deviceType': 'ios'
+    }
+    spyOn(pushAdapter, 'send').and.callThrough();
+    var pushController = new PushController();
+    reconfigureServer({
+      push: { adapter: pushAdapter }
+    }).then(() => {
+      var installations = [];
+      while (installations.length != 5) {
+        const installation = new Parse.Object("_Installation");
+        installation.set("installationId", "installation_" + installations.length);
+        installation.set("deviceToken", "device_token_" + installations.length)
+        installation.set("badge", installations.length);
+        installation.set("originalBadge", installations.length);
+        installation.set("deviceType", "ios");
+        installations.push(installation);
+      }
+      installations[0].set('localeIdentifier', 'fr-CA');
+      installations[1].set('localeIdentifier', 'fr-FR');
+      installations[2].set('localeIdentifier', 'en-US');
+      return Parse.Object.saveAll(installations);
+    }).then(() => {
+      return pushController.sendPush(payload, where, config, auth)
+    }).then(() => {
+      // Wait so the push is completed.
+      return new Promise((resolve) => { setTimeout(() => { resolve(); }, 1000); });
+    }).then(() => {
+      expect(pushAdapter.send.calls.count()).toBe(2);
+      const firstCall = pushAdapter.send.calls.first();
+      expect(firstCall.args[0].data).toEqual({
+        alert: 'Hello!'
+      });
+      expect(firstCall.args[1].length).toBe(3); // 3 installations
+
+      const lastCall = pushAdapter.send.calls.mostRecent();
+      expect(lastCall.args[0].data).toEqual({
+        alert: 'Bonjour'
+      });
+      expect(lastCall.args[1].length).toBe(2); // 2 installations
+      // No installation is in es so only 1 call for fr, and another for default
+      done();
+    }).catch(done.fail);
+  });
 });