Don't use switch on string, for Java 6 compatibility

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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=75322297

core/src/main/java/com/google/net/stubby/newtransport/netty/Http2Negotiator.java

@@ -263,26 +263,29 @@ public class Http2Negotiator {
               @Override
               public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                 String methodName = method.getName();
-                switch (methodName) {
+                if ("supports".equals(methodName)) {
-                  case "supports":
                   // both
                   return true;
-                  case "unsupported":
+                }
+                if ("unsupported".equals(methodName)) {
                   // both
                   removeMethod.invoke(null, engine);
                   protocolNegotiated.setException(new IllegalStateException(
                       "ALPN/NPN protocol " + HTTP_VERSION_NAME + " not supported by server"));
                   return null;
-                  case "protocols":
+                }
+                if ("protocols".equals(methodName)) {
                   // ALPN only
                   return ImmutableList.of(HTTP_VERSION_NAME);
-                  case "selected":
+                }
+                if ("selected".equals(methodName)) {
                   // ALPN only
                   // Only 'supports' one protocol so we know what was selected.
                   removeMethod.invoke(null, engine);
                   protocolNegotiated.set(null);
                   return null;
-                  case "selectProtocol":
+                }
+                if ("selectProtocol".equals(methodName)) {
                   // NPN only
                   @SuppressWarnings("unchecked")
                   List<String> names = (List<String>) args[0];