EXAMPLE: libbinderdebug: generic metric collector

Example binary to collect binder threadpool
usage plus client count for metric dashboards.

Note: dumpsys is already doing similar things as this.
If we have the generic format, we would probably
re-write /system/bin/dumpsys to support that format
rather than needing to use this other binary.

Bug: N/A
Test: N/A
Change-Id: I9f300f05e9475b6d39e8071e5843eccfb3584bc4