prebuilt.conf: updating FULL_BINHOST

Change-Id: Iafa13043aa018b92da33fe6866ab32559afd267a
diff --git a/overlay-arm64-generic/prebuilt.conf b/overlay-arm64-generic/prebuilt.conf
index 12cacb0..ebc0ddc 100644
--- a/overlay-arm64-generic/prebuilt.conf
+++ b/overlay-arm64-generic/prebuilt.conf
@@ -1 +1 @@
-FULL_BINHOST="gs://chromeos-prebuilt/board/arm64-generic/full-R77-12299.0.0-rc2/packages/"
+FULL_BINHOST="gs://chromeos-prebuilt/board/arm64-generic/full-R77-12300.0.0-rc1/packages/"