Reland "Change HIDL fmq tests to use int32_t for payload" am: 7a26802481 am: 8980ac3b5f am: 99ace1c2f4

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/1434353

Change-Id: Idc5099535d2962e06988c8181e04fce1c401ae30