Upgrade Truth to 0.30

IterableSubject is no longer generic, which improves readability in
some callers.

Change-Id: I948a356089f60f1f02f291a2f433eec67571424b

gerrit-server/src/test/java/com/google/gerrit/server/config/RepositoryConfigTest.java

@@ -145,7 +145,6 @@ public class RepositoryConfigTest {
         RepositoryConfig.OWNER_GROUP_NAME, ownerGroups);
   }
 
-  @SuppressWarnings("cast")
   @Test
   public void testBasePathWhenNotConfigured() {
     assertThat((Object)repoCfg.getBasePath(new NameKey("someProject"))).isNull();
@@ -159,7 +158,6 @@ public class RepositoryConfigTest {
         .isEqualTo(basePath);
   }
 
-  @SuppressWarnings("cast")
   @Test
   public void testBasePathForSpecificFilter() {
     String basePath = "/someAbsolutePath/someDirectory";