Modify WindowUntrustedTouchTest for opacity cap In topic CL. Test: atest -d android.server.wm.WindowUntrustedTouchTest Bug: 218777508 Merged-In: I072bdc628034abce81bc74cc4fb747b38cf5dc1f Change-Id: I072bdc628034abce81bc74cc4fb747b38cf5dc1f