Update build-instructions.md file reference location in ui/README.md
Update build-instructions.md file reference location in ui/README.md

Change-Id: If67efe395c59f145b75c764f48bde8f4e06b362c

google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto