Remove `@Nullable` annotation from `escapeJavaType` method.

Summary:
The type parameter is annotated with @Nullable, but the parameter
should not actually be null because it is being dereferenced within
the method.

Remove the annotation.

https://github.com/facebook/buck/pull/60

Test Plan: Run some test builds.
diff --git a/src/com/facebook/buck/parcelable/Parser.java b/src/com/facebook/buck/parcelable/Parser.java
index 8af52fc..41545c1 100644
--- a/src/com/facebook/buck/parcelable/Parser.java
+++ b/src/com/facebook/buck/parcelable/Parser.java
@@ -87,7 +87,7 @@
    * We allow { and } to be used in place of < and > for Java generics in our XML
    * descriptor files.
    */
-  private static String escapeJavaType(@Nullable String type) {
+  private static String escapeJavaType(String type) {
     return type.replace('{', '<').replace('}', '>');
   }