Update Gerrit API to 2.15.18

Note that the sha1 for the gerrit-plugin-gwtui artifact is the same
as version 2.15.17.

Change-Id: Id76ffbb0d73adecf24c46ce07c4ae84342737f73
diff --git a/gerrit_api.bzl b/gerrit_api.bzl
index 4666572..27ca508 100644
--- a/gerrit_api.bzl
+++ b/gerrit_api.bzl
@@ -6,7 +6,7 @@
 gerrit_api is rule for fetching Gerrit plugin API using Bazel.
 """
 
-VER = "2.15.17"
+VER = "2.15.18"
 
 def gerrit_api():
     bouncycastle_repos()
@@ -15,7 +15,7 @@
     maven_jar(
         name = "gerrit_plugin_api",
         artifact = "com.google.gerrit:gerrit-plugin-api:" + VER,
-        sha1 = "399543dc5664c61b3f19bfd6db73dfa74289079d",
+        sha1 = "ea03c6d58c96b2e9d41602862ed713612e558e3e",
     )
     maven_jar(
         name = "gerrit_plugin_gwtui",
@@ -26,7 +26,7 @@
     maven_jar(
         name = "gerrit_acceptance_framework",
         artifact = "com.google.gerrit:gerrit-acceptance-framework:" + VER,
-        sha1 = "52fb9ef66b6f1d378a7b3c2cc0b4ef6ea730941b",
+        sha1 = "21cc57fb3ba9cc0235bc7bec990bf23e241ad395",
     )
     native.bind(
         name = "gerrit-plugin-api",