Merge "libcutils must check /sys/kernel/tracing for tracefs first" am:...

Merge "libcutils must check /sys/kernel/tracing for tracefs first" am: 7259edac am: 2ae99763 am: 18feb083

Original change: https://android-review.googlesource.com/c/platform/system/core/+/1427529

Change-Id: Id4bafb7917d79239dc1785a4b57875491522285d