Encode value of key element in PostPolicy (#1175)

Author: balamurugana

api/src/main/java/io/minio/PostPolicy.java

@@ -90,6 +90,7 @@ public void addEqualsCondition(@Nonnull String element, @Nonnull String value) {
       throw new IllegalArgumentException(element + " cannot be set");
     }
 
+    if ("key".equals(element)) value = S3Escaper.encodePath(value);
     conditions.get(EQ).put(element, value);
   }
 
@@ -123,6 +124,7 @@ public void addStartsWithCondition(@Nonnull String element, @Nonnull String valu
       throw new IllegalArgumentException(element + " cannot be set");
     }
 
+    if ("key".equals(element)) value = S3Escaper.encodePath(value);
     conditions.get(STARTS_WITH).put(element, value);
   }