Correct Preconditions.checkNotNull usage.

Reference to check should be first parameter.

Bug: 146340409

Test: Treehugger
Change-Id: If5bd0cf8943c43c42a77997741edcc5b64178804

services/core/java/com/android/server/pm/PackageManagerService.java

@@ -12872,7 +12872,7 @@ public class PackageManagerService extends IPackageManager.Stub
 
     @Override
     public String[] getUnsuspendablePackagesForUser(String[] packageNames, int userId) {
-        Preconditions.checkNotNull("packageNames cannot be null", packageNames);
+        Preconditions.checkNotNull(packageNames, "packageNames cannot be null");
         mContext.enforceCallingOrSelfPermission(Manifest.permission.SUSPEND_APPS,
                 "getUnsuspendablePackagesForUser");
         final int callingUid = Binder.getCallingUid();