[automerger skipped] Upgrade emulator to emu-master-dev build 6278574 am: 9c1912d89f -s ours am: 9473c9c214 -s ours am: d344b9f8ec -s ours am: 6947714f42 -s ours

am skip reason: Change-Id I54ae600c215da62c3375c85209ea9e8990597202 with SHA-1 924aa30ed3 is in history

Change-Id: Ifbf25afdfa5746e82e5c135bc37cbe1a2b52b209