Merge "Migrate HelloPDK to Soong" am: 4af5db9f95 am: 365e5273f3 am: 676b316803 am: 5c3fbc9e96 am: e28d6595d8

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

Change-Id: I97bbf2240d85277e9be12f0015168864bc1cc55a
tree: 7546851887a05858d9790eb8869b5778bf4cd70e
  1. apps/
  2. build/
  3. util/
  4. .gitignore
  5. README