adding /out/soong_injection/metrics/converted_modules_path_map.json

This file can be used by atest/scripts/tools to determine which modules
have been converted and what their bazel build path is.

Test: b build //packages/modules/adb/...
will generate the file at /out/soong_injection/metrics/converted_modules_path_map.json
Also added a unit test to check that the file is created.

{
  "adbd": "//packages/modules/adb",
  "adbd_test": "//packages/modules/adb",
  "add_ext4_encrypt": "//external/e2fsprogs/contrib",
  ....
}

Change-Id: Ibd424c487840d84c8a4fb635828a73541220b36b