Update Changelog for 15.7.0-rc.2

changelog.txt

@@ -1,5 +1,34 @@
 == Changelog ==
 
+= 15.7.0-rc.2 =
+
+
+
+## Changelog
+
+### Bug Fixes
+
+#### Block Library
+- Cover: Re-instate overflow:Hidden rule to fix issue with border radius. ([50209](https://github.com/WordPress/gutenberg/pull/50209))
+- Fix site logo preview image size with long filenames. ([50242](https://github.com/WordPress/gutenberg/pull/50242))
+
+#### Global Styles
+- Layout: Fix issue where saving user global styles included layout definitions in layout settings. ([50268](https://github.com/WordPress/gutenberg/pull/50268))
+
+
+## First time contributors
+
+The following PRs were merged by first time contributors:
+
+
+
+## Contributors
+
+The following contributors merged PRs in this release:
+
+@andrewserong @ntsekouras
+
+
 = 15.7.0-rc.1 =