Soong: Add build_error proto raw file to $(OUT_DIR).

Soong_ui produces a build_error raw file to $(OUT_DIR) where
the file contains a list of build action errors. Each build action
error represents an error raised by a command. The build_error file
is populated if there was a build error.

Bug: b/132969697
Test: Ran m for successful build. Introduced a broken build change,
      ran m and verified using printproto that build_error was
      generated successfully.

Change-Id: I690ca1778b4e56f144a3173ba1d16d8494c32c15