Simplify a logging message (3/n)

VersionedPackage overrides toString() which can be used in string
concatenation.

Bug: 147028082
Test: build doesn't fail
Change-Id: Id7ba8465c8e5df6e7c409e5b0c14e99eb31bbcef

services/core/java/com/android/server/rollback/RollbackPackageHealthObserver.java

@@ -120,9 +120,7 @@ public final class RollbackPackageHealthObserver implements PackageHealthObserve
 
         RollbackInfo rollback = getAvailableRollback(failedPackage);
         if (rollback == null) {
-            Slog.w(TAG, "Expected rollback but no valid rollback found for package: [ "
-                    + failedPackage.getPackageName() + "] with versionCode: ["
-                    + failedPackage.getVersionCode() + "]");
+            Slog.w(TAG, "Expected rollback but no valid rollback found for " + failedPackage);
             return false;
         }
         rollbackPackage(rollback, failedPackage, rollbackReason);