Allow to query NetworkStats for TYPE_PROXY

Test: atest FrameworksNetTests CtsNetTestCases
Bug: 307217169

Change-Id: I006e3191a8c6100af3d2906d5d37f4e38a3db519

framework-t/src/android/net/NetworkStatsCollection.java

@@ -31,6 +31,7 @@ import static android.net.NetworkStats.UID_ALL;
 import static android.net.NetworkTemplate.MATCH_BLUETOOTH;
 import static android.net.NetworkTemplate.MATCH_ETHERNET;
 import static android.net.NetworkTemplate.MATCH_MOBILE;
+import static android.net.NetworkTemplate.MATCH_PROXY;
 import static android.net.NetworkTemplate.MATCH_WIFI;
 import static android.net.TrafficStats.UID_REMOVED;
 import static android.text.format.DateUtils.WEEK_IN_MILLIS;
@@ -784,6 +785,7 @@ public class NetworkStatsCollection implements FileRotator.Reader, FileRotator.W
         dumpCheckin(pw, start, end, new NetworkTemplate.Builder(MATCH_WIFI).build(), "wifi");
         dumpCheckin(pw, start, end, new NetworkTemplate.Builder(MATCH_ETHERNET).build(), "eth");
         dumpCheckin(pw, start, end, new NetworkTemplate.Builder(MATCH_BLUETOOTH).build(), "bt");
+        dumpCheckin(pw, start, end, new NetworkTemplate.Builder(MATCH_PROXY).build(), "proxy");
     }
 
     /**

framework-t/src/android/net/NetworkTemplate.java

@@ -1170,7 +1170,7 @@ public final class NetworkTemplate implements Parcelable {
          * @param matchRule the target match rule to be checked.
          */
         private static void assertRequestableMatchRule(final int matchRule) {
-            if (!isKnownMatchRule(matchRule) || matchRule == MATCH_PROXY) {
+            if (!isKnownMatchRule(matchRule)) {
                 throw new IllegalArgumentException("Invalid match rule: "
                         + getMatchRuleName(matchRule));
             }

tests/common/java/android/net/netstats/NetworkTemplateTest.kt

@@ -62,11 +62,6 @@ class NetworkTemplateTest {
             }
         }
 
-        // Verify hidden match rules cannot construct templates.
-        assertFailsWith<IllegalArgumentException> {
-            NetworkTemplate.Builder(MATCH_PROXY).build()
-        }
-
         // Verify template which matches metered cellular and carrier networks with
         // the given IMSI. See buildTemplateMobileAll and buildTemplateCarrierMetered.
         listOf(MATCH_MOBILE, MATCH_CARRIER).forEach { matchRule ->
@@ -170,9 +165,9 @@ class NetworkTemplateTest {
                     assertEquals(expectedTemplate, it)
                 }
 
-        // Verify template which matches ethernet and bluetooth networks.
+        // Verify template which matches ethernet, bluetooth and proxy networks.
         // See buildTemplateEthernet and buildTemplateBluetooth.
-        listOf(MATCH_ETHERNET, MATCH_BLUETOOTH).forEach { matchRule ->
+        listOf(MATCH_ETHERNET, MATCH_BLUETOOTH, MATCH_PROXY).forEach { matchRule ->
             NetworkTemplate.Builder(matchRule).build().let {
                 val expectedTemplate = NetworkTemplate(matchRule,
                         emptyArray<String>() /*subscriberIds*/, emptyArray<String>(),