[automerge] Fix return values in AIDL multi-HAL shim 2p: eae8adf209

Original change: https://googleplex-android-review.googlesource.com/c/platform/hardware/interfaces/+/17696540

Bug: 228645167
Change-Id: I008c5b1b7ee3b6f15cb1b423661b33554cb6ea43