Unhide inInputShareable in BitmapFactory.Options.

The variable works together with inPurgeable, which has been unhidden in
https://android-git.corp.google.com/g/Gerrit#change,2870.

graphics/java/android/graphics/BitmapFactory.java

@@ -125,8 +125,6 @@ public class BitmapFactory {
          * false, then this field is ignored. If inPurgeable is true, then this
          * field determines whether the bitmap can share a reference to the
          * input data (inputstream, array, etc.) or if it must make a deep copy.
-         *
-         * @hide pending API council approval
          */
         public boolean inInputShareable;