Move release notes to 21.8

Author: selanthiraiyan

RELEASE-NOTES.txt

@@ -8,6 +8,7 @@
 - [*] Improved image loading in Blaze Campaign Creation: displays a redacted and shimmering effects when loading product image and falls back to a placeholder if no image is available. [https://github.com/woocommerce/woocommerce-ios/pull/15098]
 - [*] Product List: Display syncing animation on items with image upload in progress [https://github.com/woocommerce/woocommerce-ios/pull/15052]
 - [*] Background image upload: Fix missing error notice in iPhones [https://github.com/woocommerce/woocommerce-ios/pull/15117]
+- [*] Filters applied in product selector no longer affect the main product list screen. [https://github.com/woocommerce/woocommerce-ios/pull/14764]
 
 21.7
 -----
@@ -41,8 +42,6 @@
 
 21.4
 -----
-- [*] Filters applied in product selector no longer affect the main product list screen. [https://github.com/woocommerce/woocommerce-ios/pull/14764]
-
 - [**] Store Picker: Sites can now be hidden from the list for a more focused experience for agencies. [https://github.com/woocommerce/woocommerce-ios/pull/14780]
 - [*] Fetching plugins info in the app (e.g. payments onboarding) is more resilient to unexpected types in unrelated fields in the system status response. This used to result in a decoding error. [https://github.com/woocommerce/woocommerce-ios/pull/14781]
 - [*] Fixed an issue on iPad where creating an order with a custom amount type failed after selecting and deselecting a product. [https://github.com/woocommerce/woocommerce-ios/pull/14789]