Remove complication id from entry mapping on removal.

This changelist ensures a complication's id is removed from the
ComplicationLayoutEngine's internal entry mapping when the complication
is removed. This can happen when complications are singletons.

Bug: 224809882
Test: atest ComplicationLayoutEngineTest#testDoubleRemoval
Change-Id: Ie350e7ab08e909af43ad9d7eadd0ca82c6ad3aa0