Add system server jars expressed in make in the system server classpath.

This was missed in:
https://android-review.googlesource.com/c/platform/build/soong/+/1180134

Test: lunch and build ARC, check SYSTEMSERVERCLASSPATH
Bug: 148944771
Bug: 141785760
Bug: 140451054
Change-Id: I619aee5441f7233010067a6c780e978f38ba7796