React DevTools 4.27.6 -> 4.27.7 (facebook#26780)

Summary:
List of changes:
* DevTools: fix backend activation ([hoxyq](https://github.com/hoxyq) in
[facebook#26779](facebook/react#26779))
* fix[dynamic-scripts-injection]: unregister content scripts before
registration ([hoxyq](https://github.com/hoxyq) in
[facebook#26765](facebook/react#26765))

DiffTrain build for commit facebook/react@783e7fc.

Changelog: [Internal]

<< DO NOT EDIT BELOW THIS LINE >>

Reviewed By: sammy-SC

Differential Revision: D45575104

Pulled By: tyao1

fbshipit-source-id: c065eb8f1f200170f611b5becc0332109f22ef71

packages/react-native/Libraries/Renderer/REVISION

@@ -1 +1 @@
-377c5175f78e47a3f01d323ad6528a696c88b76e
+783e7fcfa3e354b3be13f5403fc2fd2260db00b4