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

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

briar-android/src/org/briarproject/system/AndroidLocationUtils.java

@@ -0,0 +1,46 @@
+package org.briarproject.system;
+
+import java.util.Locale;
+import java.util.logging.Logger;
+
+import org.briarproject.api.system.LocationUtils;
+
+import roboguice.inject.ContextSingleton;
+import android.annotation.SuppressLint;
+import android.content.Context;
+import android.telephony.TelephonyManager;
+import android.text.TextUtils;
+
+import com.google.inject.Inject;
+
+@ContextSingleton
+class AndroidLocationUtils implements LocationUtils {
+
+	private static final Logger LOG =
+			Logger.getLogger(AndroidLocationUtils.class.getName());
+
+	final Context context;
+	
+	@Inject
+	public AndroidLocationUtils(Context context) {
+		this.context = context;
+	}
+	
+	@SuppressLint("DefaultLocale")
+	@Override
+	public String getCurrentCountry() {
+		String countryCode;
+		countryCode = getCountryFromPhoneNetwork();
+		if (!TextUtils.isEmpty(countryCode)) {
+			return countryCode.toUpperCase(); // android api gives lowercase for some reason
+		}
+		LOG.warning("Could not determine current country; fall back to user-defined locale");
+		return Locale.getDefault().getCountry();
+	}
+	
+	String getCountryFromPhoneNetwork() {
+		TelephonyManager tm = (TelephonyManager)context.getSystemService(Context.TELEPHONY_SERVICE);
+		return tm.getNetworkCountryIso();
+	}
+	
+}