Handle configuration splits when creating the class loader context

Configuration splits have no dependencies which can lead to exceptions
when computing their class loader context.

In general, we do not need to compute the class loader context for apks
without code.

This CL addresses the issue by ignoring "code" paths with no actual code.

Bug: 65159159
Test: adb install-multiple config_splits
      runtest -x
services/tests/servicestests/src/com/android/server/pm/dex/DexoptUtilsTest.java

Change-Id: Ida1eb901eecba4a4266de73022f6ee4659367873