MINOR: [Swift] Add missing Bool type to decoder type checks (apache#4…

…2064)

### What changes are included in this PR?

Adding Bool and Bool? as valid types for decoding.

Authored-by: Alva Bandy <[email protected]>
Signed-off-by: Sutou Kouhei <[email protected]>

swift/Arrow/Sources/Arrow/ArrowDecoder.swift

@@ -146,6 +146,7 @@ private struct ArrowUnkeyedDecoding: UnkeyedDecodingContainer {
             type == UInt32?.self || type == UInt64?.self ||
             type == String?.self || type == Double?.self ||
             type == Float?.self || type == Date?.self ||
+            type == Bool?.self || type == Bool.self ||
             type == Int8.self || type == Int16.self ||
             type == Int32.self || type == Int64.self ||
             type == UInt8.self || type == UInt16.self ||
@@ -359,7 +360,8 @@ private struct ArrowSingleValueDecoding: SingleValueDecodingContainer {
             type == UInt8.self || type == UInt16.self ||
             type == UInt32.self || type == UInt64.self ||
             type == String.self || type == Double.self ||
-            type == Float.self || type == Date.self {
+            type == Float.self || type == Date.self ||
+            type == Bool.self {
             return try self.decoder.doDecode(0)!
         } else {
             throw ArrowError.invalid("Type \(type) is currently not supported")