avoid "override" with "final" am: 31aa264b6c am: a4340538f8 am: 756c770aa7

Original change: https://android-review.googlesource.com/c/platform/system/tools/aidl/+/1701973

Change-Id: Ifcbd7f990b6fdfe370b0e2f75af622e3d0c3cd34