[zircon][prebuilt] Add AEMU

DX-939 #comment

Test: scripts/download-prebuilt && prebuilt/downloads/aemu/emulator
Change-Id: I001ddcf3ccc1875520f846d0442aa54a52ba960b

zircon/prebuilt/zircon.ensure

@@ -60,3 +60,7 @@ infra/ninja/${os}-${arch=amd64} version:1.8.2
 @Subdir banjo
 # TODO(BLD-341): replace ${os}-${arch=amd64} with ${platform}
 fuchsia/tools/banjo_bin/${os}-${arch=amd64} git_revision:74d433b8ae7709785b80159b39cfcef831edf19f
+
+# AEMU
+@Subdir aemu
+fuchsia/third_party/aemu/${os}-${arch=amd64} git_revision:2da1707469c501168757c820cf5459c64a2ca128

zircon/prebuilt/zircon.versions

@@ -29,6 +29,14 @@ fuchsia/sysroot/linux-arm64
 	git_revision:a4aaacde9d37ccf91a0f8dc8267cb7ad5d9be283
 	B1w-KMj3c3107ZQ3i05ID0Keq_kDPXLmwAkwzn2LmTIC
 
+fuchsia/third_party/aemu/linux-amd64
+	git_revision:2da1707469c501168757c820cf5459c64a2ca128
+	TPjWCtgP37HcOdWjTeE7A9BWnAT-r8SUyAnilNonAiEC
+
+fuchsia/third_party/aemu/mac-amd64
+	git_revision:2da1707469c501168757c820cf5459c64a2ca128
+	SGJMEvb8W_lcAZ7feVGfLPraGu6BUVlIkkKZPgIuo1YC
+
 fuchsia/third_party/qemu/linux-amd64
 	git_revision:533bf2563d0213a7e002d9fcde75519d30ffa70f,1
 	JpS4LjitK-9eP-VvBt27WXALLFbP0iw7IQWWYGI5RXsC