bazel: set slow tests to size="medium".

Per Bazel's Test Encyclopedia, this specifies a 300s timeout.

Change-Id: I39d8169c991ab9ad13827020d25804f7d5af436d

gerrit-acceptance-tests/tests.bzl

@@ -7,16 +7,12 @@ BOUNCYCASTLE = [
 
 def acceptance_tests(
     group,
-    srcs,
-    flaky = 0,
     deps = [],
     labels = [],
     vm_args = ['-Xmx256m'],
     **kwargs):
   junit_tests(
     name = group,
-    srcs = srcs,
-    flaky = flaky,
     deps = deps + BOUNCYCASTLE + [
       '//gerrit-acceptance-tests:lib',
     ],
@@ -24,6 +20,7 @@ def acceptance_tests(
       'acceptance',
       'slow',
     ],
+    size = "medium",
     jvm_flags = vm_args,
     **kwargs
   )

gerrit-elasticsearch/BUILD

@@ -35,6 +35,7 @@ junit_tests(
   name = 'elasticsearch_tests',
   tags = ['elastic', 'flaky'],
   srcs = glob(['src/test/java/**/*.java']),
+  size = "medium",
   deps = [
     ':elasticsearch',
     '//gerrit-extension-api:api',

gerrit-server/BUILD

@@ -191,6 +191,7 @@ java_library(
 junit_tests(
   name = 'query_tests',
   srcs = QUERY_TESTS,
+  size = "medium",
   deps = TESTUTIL_DEPS + [
     ':testutil',
     '//gerrit-antlr:query_exception',
@@ -209,6 +210,7 @@ junit_tests(
     exclude = TESTUTIL + PROLOG_TESTS + PROLOG_TEST_CASE + QUERY_TESTS
   ),
   resources = glob(['src/test/resources/com/google/gerrit/server/mail/*']),
+  size = "medium",
   deps = TESTUTIL_DEPS + [
     ':testutil',
     '//gerrit-antlr:query_exception',