Updated text to what is actually shown on the device (facebook#189)

* Updated text to what is actually shown on the device

* Updated as previous adb reverse command was no longer working

docs/running-on-device.md

@@ -287,7 +287,13 @@ You can use this method if your device is running Android 5.0 (Lollipop) or newe
 Run the following in a command prompt:
 
 ```
-$ adb reverse tcp:8081 tcp:8081
+$ adb -s <device name> reverse tcp:8081 tcp:8081
+```
+
+To find the device name, run the following adb command:
+
+```
+$ adb devices
 ```
 
 You can now enable Live reloading from the [Developer menu](debugging.md#accessing-the-in-app-developer-menu). Your app will reload whenever your JavaScript code has changed.
@@ -314,7 +320,7 @@ Open a terminal and type `/sbin/ifconfig` to find your machine's IP address.
 2. Open your React Native app on your device.
 3. You'll see a [red screen with an error](debugging.md#in-app-errors-and-warnings). This is OK. The following steps will fix that.
 4. Open the in-app [Developer menu](debugging.md#accessing-the-in-app-developer-menu).
-5. Go to **Dev Settings** → **Debug server host for device**.
+5. Go to **Dev Settings** → **Debug server host & port for device**.
 6. Type in your machine's IP address and the port of the local dev server (e.g. 10.0.1.1:8081).
 7. Go back to the **Developer menu** and select **Reload JS**.