Summary:
RCTKeyboardObserver only uses the bridge to avoid sending events during a reload. See D6573855 (https://github.com/facebook/react-native/commit/d9c658566a14ce8767d87435264997aa18dd08e4) for reference.
In bridgeless mode, the bridge is expected to always be nil, as the module uses `invokeJS` block to send events instead.
Changelog: [Internal]
Reviewed By: shergin
Differential Revision: D23176990
fbshipit-source-id: 7946c9c2684d7d9ea0a606bad375309a5530a719