Revert "Revert "Testing AIDL delegator class with RPC""

This reverts commit 2fcd479e.

The original commit was submitted with the system/tools/aidl commit that
broke the build.
That commit is fixed with the revert of the revert.
So this revert is being reverted..

Test: atest binderRpcTest
Bug: 198785815
Change-Id: I6f3fc85c9398801f7db0c81c8874d4c27dc36055