Fix proguard rules for Struct in NetworkStack am: 9a82bbf368 am: 9aaeab539b am: 54024858a6

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/1674688

Change-Id: I4262236535ec9e1c7ff46ca84723e673647fb3c9
tree: d785781d58624b2dff971427db405d16b857eb8a
  1. tests/
  2. Tethering/
  3. .gitignore
  4. OWNERS
  5. PREUPLOAD.cfg
  6. TEST_MAPPING