Added amazon-fireos platform + some of the fixes in android code.
Updated amazon-fireos platform + reverting some of the fixes in android code.

1. We need to pass Looper.getMainLooper() to the requestLocationUpdates method. Otherwise, we get a RUntime Exception : Can't create handler inside thread that has not called Looper.prepare(). This change is only required for EmbeddedWebView

2. Removed all changes added to android folder

3. Updated plugin.xml to use amazon folder instead of android for the amazon-firos port

4. Change to use amazon-fireos as a platform if user agent string contains 'cordova-amazon-fireos'