Revert "libmdnssd is only used by adbd."

This reverts commit 1ecbeae2.

Reason for revert: Prime candidate as culprit for build breakage
build_id/11678886
 
Bug: 333111739
(cherry picked from https://android-review.googlesource.com/q/commit:0930977b5561ef8f0f2ec5b43d85f9820a60d4c3)
Merged-In: I24ee63b7cfe738e505e691b2d111c4a816513657
Change-Id: I24ee63b7cfe738e505e691b2d111c4a816513657