Use https to access cloud storage bucket

Bug: 148609216
Change-Id: I3cbfe6cb14d98ca600f9f9b61687001af6e4895e
diff --git a/tools/update_prebuilds_in_android.py b/tools/update_prebuilds_in_android.py
index ae1ed2c..f3a0923 100755
--- a/tools/update_prebuilds_in_android.py
+++ b/tools/update_prebuilds_in_android.py
@@ -12,7 +12,7 @@
 import utils
 import urllib
 
-BUILD_ROOT = "http://storage.googleapis.com/r8-releases/raw/"
+BUILD_ROOT = "https://storage.googleapis.com/r8-releases/raw/"
 MASTER_BUILD_ROOT = "%smaster/" % BUILD_ROOT
 
 JAR_TARGETS_MAP = {