Consistent dump() permission checking.

This change introduces new methods on DumpUtils that can check if the
caller has DUMP and/or PACKAGE_USAGE_STATS access.  It then moves all
existing dump() methods to use these checks so that we emit
consistent error messages.

Test: cts-tradefed run commandAndExit cts-dev -m CtsSecurityTestCases -t android.security.cts.ServicePermissionsTest
Bug: 32806790
Change-Id: Iaff6b9506818ee082b1e169c89ebe1001b3bfeca
diff --git a/services/core/java/com/android/server/net/NetworkPolicyManagerService.java b/services/core/java/com/android/server/net/NetworkPolicyManagerService.java
index f180c50..8227753 100644
--- a/services/core/java/com/android/server/net/NetworkPolicyManagerService.java
+++ b/services/core/java/com/android/server/net/NetworkPolicyManagerService.java
@@ -181,6 +181,7 @@
 import com.android.internal.notification.SystemNotificationChannels;
 import com.android.internal.telephony.PhoneConstants;
 import com.android.internal.util.ArrayUtils;
+import com.android.internal.util.DumpUtils;
 import com.android.internal.util.FastXmlSerializer;
 import com.android.internal.util.IndentingPrintWriter;
 import com.android.server.DeviceIdleController;
@@ -2585,7 +2586,7 @@
 
     @Override
     protected void dump(FileDescriptor fd, PrintWriter writer, String[] args) {
-        mContext.enforceCallingOrSelfPermission(DUMP, TAG);
+        if (!DumpUtils.checkDumpPermission(mContext, TAG, writer)) return;
 
         final IndentingPrintWriter fout = new IndentingPrintWriter(writer, "  ");