Merge "Migrate HelloPDK to Soong" am: 4af5db9f95

Original change: https://android-review.googlesource.com/c/platform/pdk/+/1859594

Change-Id: I73bdcde76baf045f848ea8d443cba2a1d52e051e
tree: 7546851887a05858d9790eb8869b5778bf4cd70e
  1. apps/
  2. build/
  3. util/
  4. .gitignore
  5. README