Revert^4 Build only the needed run-test shards with "test.py -b -t XXX"

This reverts commit 592c561dac5b6024cc18ddd9a946000597559c51.

Reason for revert: Reland

Change-Id: I10f5755be2d8590174b66075e8c39b56ae3b14f3
7 files changed