Add some missing @Deprecated annotations.

These should always go hand-in-hand with @deprecated Javadoc
annotations.

Change-Id: I0e54616d39777d43f9763a702ca0fbc381e6ed49
diff --git a/src/main/java/com/android/volley/toolbox/JsonRequest.java b/src/main/java/com/android/volley/toolbox/JsonRequest.java
index 95f4ecb..2d58f40 100644
--- a/src/main/java/com/android/volley/toolbox/JsonRequest.java
+++ b/src/main/java/com/android/volley/toolbox/JsonRequest.java
@@ -48,6 +48,7 @@
      *
      * @deprecated Use {@link #JsonRequest(int, String, String, Listener, ErrorListener)}.
      */
+    @Deprecated
     public JsonRequest(String url, String requestBody, Listener<T> listener,
             ErrorListener errorListener) {
         this(Method.DEPRECATED_GET_OR_POST, url, requestBody, listener, errorListener);
@@ -71,6 +72,7 @@
     /**
      * @deprecated Use {@link #getBodyContentType()}.
      */
+    @Deprecated
     @Override
     public String getPostBodyContentType() {
         return getBodyContentType();
@@ -79,6 +81,7 @@
     /**
      * @deprecated Use {@link #getBody()}.
      */
+    @Deprecated
     @Override
     public byte[] getPostBody() {
         return getBody();