Import Android SDK Platform-Tools 28 [4456821]

/google/data/ro/projects/android/fetch_artifact \
    --bid 4456821 \
    --target sdk_phone_armv7-sdk_mac \
    sdk-repo-darwin-platform-tools-4456821.zip

Pkg.Revision has been modified to appear as 28.0.0

Change-Id: If83d839d8685f0def928212ee6904ed75d1f6e80