Enable checkstyle rule for static variable names.

Enable the checkstyle rule that checks the names of
static variables and fix any violations that
are detected.

Change-Id: I2918a85b13b343285da99223829187a87ad280c3
diff --git a/conf/checkstyle/sun_checks.xml b/conf/checkstyle/sun_checks.xml
index 2e85f0e..81409fc 100644
--- a/conf/checkstyle/sun_checks.xml
+++ b/conf/checkstyle/sun_checks.xml
@@ -132,10 +132,7 @@
           <property name="severity" value="warning"/>
         </module>
 
-        <module name="StaticVariableName">
-          <property name="severity" value="warning"/>
-        </module>
-
+        <module name="StaticVariableName"/>
         <module name="TypeName"/>
 
         <!-- Checks for imports                              -->