[Reader IA] Fix showing "0 Blogs" chip until blogs are fetched

[RenanLukas]

Expected behavior

We should check with design team, but maybe we could display a progress in the chip while the subscribed blogs are being fetched, and then we hide the progress and show the actual number when we have it.

Actual behavior

We show "0 Blogs" while we're fetching the subscribed blogs, and when we have them we update the chip label with the correct number (e.g. "10 Blogs"). See video.

Steps to reproduce the behavior

• Perform a fresh install of JP and log in
• Open reader
• Select "Subscriptions" menu item: the blogs chip label will be "0 Blogs" at first and then will be replaced with the correct number.

Tested on emulator, Android 13, JPAndroid / WPAndroid 23.7-rc-1