RMX1921: Use CodeAurora ImsService implementation for RCS

There is no evidence that Qualcomm devices running a rather recent IMS
stack need to include AOSP RCS packages. RCS already worked before this
change and continues to do so, but the main goal was to get rid of some
of the RCS related log spam, which was accomplished here.

Change-Id: I219546e29d288373877e9bcd194a60ef5e09f224