Update C++ bindings and add const qualifiers to get methods.

Change-Id: I58affdfcc560ed269cd0fda0c5e74651bcfd4e4a
diff --git a/slang_rs_context.h b/slang_rs_context.h
index 7dbd409..d0f664e 100644
--- a/slang_rs_context.h
+++ b/slang_rs_context.h
@@ -140,7 +140,7 @@
     mReflectJavaPackageName = S;
     return;
   }
-  inline const std::string &getReflectJavaPackageName() {
+  inline const std::string &getReflectJavaPackageName() const {
     return mReflectJavaPackageName;
   }
 
@@ -148,7 +148,7 @@
     mRSPackageName = S;
     return;
   }
-  inline const std::string &getRSPackageName() {
+  inline const std::string &getRSPackageName() const {
     return mRSPackageName;
   }