Enable checkstyle rule to find empty code blocks

Enabled checkstyle rule that detects empty code blocks and fixed the
violations that were discovered.

Change-Id: Icc23e028f2bbabc1849ec566923aa125b2486a3b
diff --git a/conf/checkstyle/sun_checks.xml b/conf/checkstyle/sun_checks.xml
index e228d1f..2dcbd40 100644
--- a/conf/checkstyle/sun_checks.xml
+++ b/conf/checkstyle/sun_checks.xml
@@ -202,10 +202,7 @@
             <property name="allowInSwitchCase" value="true"/>
             <property name="severity" value="warning"/>
         </module>
-        <module name="EmptyBlock">
-          <property name="severity" value="warning"/>
-        </module>
-
+        <module name="EmptyBlock"/>
         <module name="LeftCurly"/>
 
         <module name="NeedBraces">