Add null check for use getSimCallManagerFromCall

NPE can occur depending on the call object when connecting the generated connection service.

Test: Make a call
Bug: 151289416

Signed-off-by: Junyeong Bak <junyeong.bak@samsung.com>
Change-Id: I5ed0ad80ba05d9d43ce4403dc4f55497f7e38973