Fix lint issues in ReactInstanceManager.java (#55375)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/55375

Fixed multiple lint errors in ReactInstanceManager.java:
- NonStaticNestedClass: Made ReactContextInitParams class static since it doesn't need to access instance members
- ClownyBooleanExpression: Removed unnecessary `if (true)` wrapper around throw statement
- DeadVariable: Removed unused devSettings variable
- EmptyCatchBlock: Added explanatory comment for InterruptedException handling

changelog: [internal] internal

Reviewed By: javache

Differential Revision: D91814708

fbshipit-source-id: ccc7e40df32972b3ccf536e08bfbb134908dbc66