csis: Remove spare imports

This is a result from auto fix while uploading change to this module.

Tag: #feature
Bug: 279572849
Test: atest BluetoothInstrumentationTests:com.android.bluetooth.csip.CsipSetCoordinatorServiceTest#testOutgoingConnectExistingUuid -- --abi x86_64
Change-Id: I81430749e804358c40795a7e17b4b897790af320