add the ability for briar-android to get the current country.

- this will be useful later for e.g. auto-disabling Tor

briar-api/src/org/briarproject/api/system/LocationUtils.java

@@ -0,0 +1,8 @@
+package org.briarproject.api.system;
+
+public interface LocationUtils {
+	
+	/** Get the country the device is currently-located in. */
+	String getCurrentCountry();
+
+}