Content Type is not set on uploaded blobs

[XVincentX]

The azure-botbuilder-blobs package is not setting the content type header for what is being uploaded as part of the state - even thought we do know it's application/json.

I have authored a fix which I would suggest to apply to this library:

diff --git a/node_modules/botbuilder-azure-blobs/src/blobsStorage.ts b/node_modules/botbuilder-azure-blobs/src/blobsStorage.ts
index a2357f3..196e736 100644
--- a/node_modules/botbuilder-azure-blobs/src/blobsStorage.ts
+++ b/node_modules/botbuilder-azure-blobs/src/blobsStorage.ts
@@ -165,6 +165,7 @@ export class BlobsStorage implements Storage {
 
                 return blob.upload(serialized, serialized.length, {
                     conditions: typeof eTag === 'string' && eTag !== '*' ? { ifMatch: eTag } : {},
+                    blobHTTPHeaders: { blobContentType: 'application/json' }
                 });
             },
             {