Codec2: Set minQP to 1 for IMS VT Call We can not reach to the target bitrate in CBR mode with default minQP when VT Call set iframe interval = -1. Set minQP=1 to generate enough bits from encoder in CBR mode. Bug: 155482704 Test: reproduce steps in bug Change-Id: If760442575b016620a78ea856d89c065223d49d9