Allow system to dump sensor hal process

Test: tested taking bugreport, sensor HAL traces show up in
      "VM TRACES JUST NOW"
Test: tested trigger ANR by `adb shell am hang --allow-restart`,
      sensor HAL traces shows up in /data/anr/traces.txt
Bug: 63096400
Change-Id: I1d012b9d9810f987be7aaf9d68abfd9c3184ac5c