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/CommonTimeManagementService.java b/services/core/java/com/android/server/CommonTimeManagementService.java
index 60b366a..07c8679 100644
--- a/services/core/java/com/android/server/CommonTimeManagementService.java
+++ b/services/core/java/com/android/server/CommonTimeManagementService.java
@@ -37,6 +37,7 @@
 import android.os.SystemProperties;
 import android.util.Log;
 
+import com.android.internal.util.DumpUtils;
 import com.android.server.net.BaseNetworkObserver;
 
 /**
@@ -177,13 +178,7 @@
 
     @Override
     protected void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
-        if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.DUMP)
-                != PackageManager.PERMISSION_GRANTED) {
-            pw.println(String.format(
-                        "Permission Denial: can't dump CommonTimeManagement service from from " +
-                        "pid=%d, uid=%d", Binder.getCallingPid(), Binder.getCallingUid()));
-            return;
-        }
+        if (!DumpUtils.checkDumpPermission(mContext, TAG, pw)) return;
 
         if (!mDetectedAtStartup) {
             pw.println("Native Common Time service was not detected at startup.  " +