Revert "Fix error swallowing in InputConnectionCommand unparcelling"

This reverts commit 11694b06 [1].

Reason for revert:
We will try another approach to implement InputConnection task
cancellation without InputConnectionCommand.

 [1]: Icd2b40e63771085cb8d88721fbdca7a089256b28

Bug: 194151409
Bug: 194567417
Change-Id: Ia404317848d74a0d8ca0606bfb07cbad36ab97c1
Test: atest CtsInputMethodTestCases:InputConnectionEndToEndTest