C2SoftAvcEnc: More QP bounding interface work

Update parsing min/max qp to handle cases where min passed
is larger than max (max is honoured and min is clipped to max)

Bug: 181830609
Bug: 182015210

Test: MediaCodec based application to set qp bounds
      and review the resulting clip's Qp values

Change-Id: If41930dd91827e11047eaa5d9d4e0fd00aa1b52c