Set OP to msg.what instead of msg.arg1 am: dfe93b3d6e am: efc3a3ff35 am: 43e571fc16

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Stk/+/12424218

Change-Id: I3ded251721193e101437127b6ec9e6c141b7d3da