Revert "ISSUE 6849488 Bluedroid stack, remove system/bluetooth."

This reverts commit b620dc60b17a5abaf88e05c1872367bf5e9c416f.

(cherry picked from commit 128db96282d907ea2b81e7598d45bba68c33d472)

Change-Id: I21227e6232c925a42597e5c8fc0fcc0585d7a876