Don't treat pthread_t as a signed value type am: a2c333c3

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/modules/Bluetooth/+/23640299



Change-Id: Ia319f7c1280834850e2a67b465bd7271a0c4c5da
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>