Remove use of ILLEGAL_ARGUMENT in hostEndpointDisconnected

Since an invalid argument to hostEndpointDisconnected should
be ignored by the HAL (and the Context Hub service), remove
the EX_ILLEGAL_ARGUMENT requirement in the Context Hub AIDL
HAL.

Bug: 216798253
Test: Compile
Change-Id: I83f08ccb998e6b494307de51f8709f3e0fbd2c99
2 files changed