[SM06] Collect mobile NetworkStats metrics by collapsed rat type

Test: adb shell cmd stats pull-source 10000~10003
      adb shell dumpsys netstats --uid
Bug: 129082217

Change-Id: I726e74f5c63a6ed456cb13ea259b58c7a33bec76

core/java/android/net/NetworkTemplate.java

@@ -34,6 +34,7 @@ import static android.net.NetworkStats.ROAMING_NO;
 import static android.net.NetworkStats.ROAMING_YES;
 import static android.net.wifi.WifiInfo.sanitizeSsid;
 
+import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.compat.annotation.UnsupportedAppUsage;
 import android.os.Parcel;
@@ -52,6 +53,8 @@ import java.io.DataInputStream;
 import java.io.DataOutputStream;
 import java.io.IOException;
 import java.util.Arrays;
+import java.util.Collection;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Objects;
 
@@ -477,6 +480,32 @@ public class NetworkTemplate implements Parcelable {
         }
     }
 
+    /**
+     * Return all supported collapsed RAT types that could be returned by
+     * {@link #getCollapsedRatType(int)}.
+     */
+    @NonNull
+    public static final int[] getAllCollapsedRatTypes() {
+        final int[] ratTypes = TelephonyManager.getAllNetworkTypes();
+        final HashSet<Integer> collapsedRatTypes = new HashSet<>();
+        for (final int ratType : ratTypes) {
+            collapsedRatTypes.add(NetworkTemplate.getCollapsedRatType(ratType));
+        }
+        // Ensure that unknown type is returned.
+        collapsedRatTypes.add(TelephonyManager.NETWORK_TYPE_UNKNOWN);
+        return toIntArray(collapsedRatTypes);
+    }
+
+    @NonNull
+    private static int[] toIntArray(@NonNull Collection<Integer> list) {
+        final int[] array = new int[list.size()];
+        int i = 0;
+        for (final Integer item : list) {
+            array[i++] = item;
+        }
+        return array;
+    }
+
     /**
      * Check if matches Wi-Fi network template.
      */