Improve the message shown when bundle download fails

Summary:
![screenshot_20160111-004544](https://cloud.githubusercontent.com/assets/1174278/12223410/cfc57586-b7fc-11e5-9f38-4d562c6e9f0a.png)
Closes #5235

Reviewed By: svcscm

Differential Revision: D2839867

Pulled By: foghina

fb-gh-sync-id: 36230e1a0d063146db11e9c1d38cea2022a89a12

ReactAndroid/src/main/res/devsupport/values/strings.xml

@@ -13,7 +13,7 @@
   <string name="catalyst_settings_title" project="catalyst" translatable="false">Catalyst Dev Settings</string>
   <string name="catalyst_jsload_title" project="catalyst" translatable="false">Please wait…</string>
   <string name="catalyst_jsload_message" project="catalyst" translatable="false">Fetching JS bundle</string>
-  <string name="catalyst_jsload_error" project="catalyst" translatable="false">Unable to download JS bundle. Did you forget to start the development server or connect your device?</string>
+  <string name="catalyst_jsload_error" project="catalyst" translatable="false">Unable to download JS bundle from the dev server.\n\nTry the following to fix the issue:\n• Ensure that the packager server is running\n• Ensure that your device/emulator is connected to your machine and has USB debugging enabled - run \'adb devices\' to see a list of connected devices\n• If you\'re on a physical device connected to the same machine, run \'adb reverse tcp:8081 tcp:8081\' to forward requests from your device\n• If your device is on the same Wi-Fi network, set \'Debug server host &amp; port for device\' in \'Dev settings\' to your machine\'s IP address and the port of the local dev server - e.g. 10.0.1.1:8081</string>
   <string name="catalyst_remotedbg_message" project="catalyst" translatable="false">Connecting to remote debugger</string>
   <string name="catalyst_remotedbg_error" project="catalyst" translatable="false">Unable to connect with remote debugger</string>
   <string name="catalyst_element_inspector" project="catalyst" translatable="false">Show Inspector</string>