Move bp2build progress proto to build/soong
We already have support to copy files from soong to internal for metrics
collection, moving the proto there allows us to reuse existing infra.
Test: b run :bp2build-progress -- report -m adb \
--proto-file=/tmp/proto.bp
Change-Id: Ib2fd3db94cb7dd54d3ce62eba770a464f71bf1c1