Modify StatsCompanionService event processing thread am: a8ea5e90c4 am: 08fab7d43c

Original change: https://android-review.googlesource.com/c/platform/packages/modules/StatsD/+/2969313

Change-Id: I2ca5ec67e50ce946e5e9b1bf60c8f26a5423374f
Signed-off-by: Automerger Merge Worker <[email protected]>