fix(avro_to_beam): parse negative int failed

Author: DKER2

Diff for: sdks/java/core/src/main/java/org/apache/beam/sdk/util/VarInt.java

@@ -102,7 +102,7 @@ public static void encode(long v, OutputStream stream) throws IOException {
   /** Decodes an integer value from the given stream. */
   public static int decodeInt(InputStream stream) throws IOException {
     long r = decodeLong(stream);
-    if (r < 0 || r >= 1L << 32) {
+    if (r >= 1L << 32) {
       throw new IOException("varint overflow " + r);
     }
     return (int) r;

Diff for: sdks/python/apache_beam/io/avroio.py

@@ -646,9 +646,9 @@ def avro_atomic_value_to_beam_atomic_value(avro_type: str, value):
   if value is None:
     return value
   elif avro_type == "int":
-    return ctypes.c_uint32(value).value
+    return ctypes.c_int32(value).value
   elif avro_type == "long":
-    return ctypes.c_uint64(value).value
+    return ctypes.c_int64(value).value
   else:
     return value