Introduce ensureListenableCapabilities

Renamed from ensureValid, this is an easier to understand name.
It is also a lot clearer when requestable capabilities also
have to be listenable.

Also move the 2 functions together.

Test: FrameworksNetTests
Change-Id: I685f924a3720846d740837a4a0fee3d88a26725a
diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index 9cf582c..a9a06e4 100644
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -6148,13 +6148,6 @@
         }
     }
 
-    private void ensureRequestableCapabilities(NetworkCapabilities networkCapabilities) {
-        final String badCapability = networkCapabilities.describeFirstNonRequestableCapability();
-        if (badCapability != null) {
-            throw new IllegalArgumentException("Cannot request network with " + badCapability);
-        }
-    }
-
     // This checks that the passed capabilities either do not request a
     // specific SSID/SignalStrength, or the calling app has permission to do so.
     private void ensureSufficientPermissionsForRequest(NetworkCapabilities nc,
@@ -6212,7 +6205,7 @@
         nai.onSignalStrengthThresholdsUpdated(thresholdsArray);
     }
 
-    private void ensureValidNetworkSpecifier(NetworkCapabilities nc) {
+    private static void ensureValidNetworkSpecifier(NetworkCapabilities nc) {
         if (nc == null) {
             return;
         }
@@ -6225,7 +6218,7 @@
         }
     }
 
-    private void ensureValid(NetworkCapabilities nc) {
+    private static void ensureListenableCapabilities(@NonNull final NetworkCapabilities nc) {
         ensureValidNetworkSpecifier(nc);
         if (nc.isPrivateDnsBroken()) {
             throw new IllegalArgumentException("Can't request broken private DNS");
@@ -6235,6 +6228,14 @@
         }
     }
 
+    private void ensureRequestableCapabilities(@NonNull final NetworkCapabilities nc) {
+        ensureListenableCapabilities(nc);
+        final String badCapability = nc.describeFirstNonRequestableCapability();
+        if (badCapability != null) {
+            throw new IllegalArgumentException("Cannot request network with " + badCapability);
+        }
+    }
+
     // TODO: Set the mini sdk to 31 and remove @TargetApi annotation when b/205923322 is addressed.
     @TargetApi(Build.VERSION_CODES.S)
     private boolean isTargetSdkAtleast(int version, int callingUid,
@@ -6327,7 +6328,6 @@
         if (timeoutMs < 0) {
             throw new IllegalArgumentException("Bad timeout specified");
         }
-        ensureValid(networkCapabilities);
 
         final NetworkRequest networkRequest = new NetworkRequest(networkCapabilities, legacyType,
                 nextNetworkRequestId(), reqType);
@@ -6469,7 +6469,6 @@
                 Binder.getCallingPid(), callingUid, callingPackageName);
         restrictRequestUidsForCallerAndSetRequestorInfo(networkCapabilities,
                 callingUid, callingPackageName);
-        ensureValid(networkCapabilities);
 
         NetworkRequest networkRequest = new NetworkRequest(networkCapabilities, TYPE_NONE,
                 nextNetworkRequestId(), NetworkRequest.Type.REQUEST);
@@ -6536,7 +6535,7 @@
         // There is no need to do this for requests because an app without CHANGE_NETWORK_STATE
         // can't request networks.
         restrictBackgroundRequestForCaller(nc);
-        ensureValid(nc);
+        ensureListenableCapabilities(nc);
 
         NetworkRequest networkRequest = new NetworkRequest(nc, TYPE_NONE, nextNetworkRequestId(),
                 NetworkRequest.Type.LISTEN);
@@ -6558,7 +6557,7 @@
         if (!hasWifiNetworkListenPermission(networkCapabilities)) {
             enforceAccessPermission();
         }
-        ensureValid(networkCapabilities);
+        ensureListenableCapabilities(networkCapabilities);
         ensureSufficientPermissionsForRequest(networkCapabilities,
                 Binder.getCallingPid(), callingUid, callingPackageName);
         final NetworkCapabilities nc = new NetworkCapabilities(networkCapabilities);