Upgrade emulator to emu-master-dev build 8499664 am: 21ed0f6dbf

Original change: https://googleplex-android-review.googlesource.com/c/platform/prebuilts/android-emulator/+/17965680

Change-Id: I2bb10c4bc9a0f5a123b2e3473c418e08e3aff7d8
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>