Fix tests for using IBase instead of IBinder.

Echoed interfaces cannot be casted properly, because
interfaceChain cannot be called. So the given vector
of interfaces is re-wrapped. This is temporary; when
b/33173166 is fixed, this change should be reverted.

Test: hidl_test

Generates: b/33173166

Change-Id: I12166f69cf04abf7485dc2455ad731b87c80b3d1