Deprecate hint as string for count

JAVA-3030

Author: jyemin

driver-core/src/main/com/mongodb/client/model/CountOptions.java

@@ -51,7 +51,9 @@ public Bson getHint() {
      * Gets the hint string to apply.
      *
      * @return the hint string, which should be the name of an existing index
+     * @deprecated Prefer {@link #getHint()}
      */
+    @Deprecated
     @Nullable
     public String getHintString() {
         return hintString;
@@ -73,7 +75,9 @@ public CountOptions hint(@Nullable final Bson hint) {
      *
      * @param hint the name of the index which should be used for the operation
      * @return this
+     * @deprecated Prefer {@link #hint(Bson)}
      */
+    @Deprecated
     public CountOptions hintString(@Nullable final String hint) {
         this.hintString = hint;
         return this;

driver-legacy/src/main/com/mongodb/client/model/DBCollectionCountOptions.java

@@ -62,7 +62,9 @@ public DBObject getHint() {
      * Gets the hint string to apply.
      *
      * @return the hint string, which should be the name of an existing index
+     * @deprecated Prefer {@link #getHint()}
      */
+    @Deprecated
     @Nullable
     public String getHintString() {
         return hintString;
@@ -84,7 +86,9 @@ public DBCollectionCountOptions hint(@Nullable final DBObject hint) {
      *
      * @param hint the name of the index which should be used for the operation
      * @return this
+     * @deprecated Prefer {@link #hint(DBObject)}
      */
+    @Deprecated
     public DBCollectionCountOptions hintString(@Nullable final String hint) {
         this.hintString = hint;
         return this;