Fix a race condition in upstream selection. am: 491999292b am: bf8a7b622d

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/1662400

Change-Id: I62d575655a0f4880f0f2c2a793bf9eb1ca9295dc
tree: 8edfe54e6f829f87465a1734c4086ac683e25139
  1. tests/
  2. Tethering/
  3. .gitignore
  4. OWNERS
  5. PREUPLOAD.cfg
  6. TEST_MAPPING