Allow testing hidden packages on PrivappPermissionsTest

PackageManager#getPackageInfo does not provide an information of hidden
packages by default. MATCH_UNINSTALLED_PACKAGES option is required.
Otherwise testPrivappPermissionsEnforcement fails due to
NameNotFoundException.

Bug: 127914632
Change-Id: If012eca98724e9e34ac307c966407e09cd251668
diff --git a/tests/tests/permission2/src/android/permission2/cts/PrivappPermissionsTest.java b/tests/tests/permission2/src/android/permission2/cts/PrivappPermissionsTest.java
index 517f451..3c69bb8 100644
--- a/tests/tests/permission2/src/android/permission2/cts/PrivappPermissionsTest.java
+++ b/tests/tests/permission2/src/android/permission2/cts/PrivappPermissionsTest.java
@@ -91,7 +91,8 @@
             }
 
             PackageInfo factoryPkg = pm
-                    .getPackageInfo(packageName, MATCH_FACTORY_ONLY | GET_PERMISSIONS);
+                    .getPackageInfo(packageName, MATCH_FACTORY_ONLY | GET_PERMISSIONS
+                        | MATCH_UNINSTALLED_PACKAGES);
 
             assertNotNull("No system image version found for " + packageName, factoryPkg);