Add more debug info for missing required package.

Bug: 226411238
Test: presubmit
Change-Id: Ie777adc8e31e82e34303b2273234d601d403e2ab

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

@@ -3536,6 +3536,8 @@ public class PackageManagerService implements PackageSender, TestUtilityService
                     EventLog.writeEvent(0x534e4554, "145981139", packageInfo.applicationInfo.uid,
                             "");
                 }
+                Log.w(TAG, "Missing required system package: " + packageName + (packageInfo != null
+                        ? ", but found with extended search." : "."));
                 return null;
             }
         } finally {