Correct the comments for radio hal types

The type of mcc and mnc is String instead of Int now. They should be an
empty string if unknown. Also added a test case for their values.

Bug: 111703979
Test: Vts
Change-Id: Ie0426453dc426ccc6cf203b315806e78511ce14d
diff --git a/current.txt b/current.txt
index af70147..b8457f8 100644
--- a/current.txt
+++ b/current.txt
@@ -390,4 +390,5 @@
 1a5ae9793223658174258b523763c557abad6fb917df0b8e3cc097fc89035811 android.hardware.neuralnetworks@1.0::types
 4310eb8272f085914952f3bfb73a8f8bb477a80e8b93596f0ea5acb58546b66d android.hardware.neuralnetworks@1.1::types
 1d4a5776614c08b5d794a5ec5ab04697260cbd4b3441d5935cd53ee71d19da02 android.hardware.radio@1.0::IRadioResponse
+271187e261b30c01a33011aea257c07a2d2f05b72943ebee89e973e997849973 android.hardware.radio@1.0::types
 1d19720d4fd38b1095f0f555a4bd92b3b12c9b1d0f560b0e9a474cd6dcc20db6 android.hardware.radio@1.2::IRadio