IOS 15.4.1 build 19E258

iOS 15.4.1 build 19E258 is the official RTM build of iOS 15.4.1, which was released to the public on 31 March 2022.

Fixes and changes

 * Fixed an issue that caused the battery to drain faster than usual after updating to iOS 15.4.
 * Fixed an issue that caused Braille devices to stop responding while navigating text or displaying an alert.
 * Fixed an issue where Made for iPhone hearing devices randomly lost connection within some third-party apps.
 * An AppleAVD issue that could allow an application to execute arbitrary code with kernel privileges was fixed.
 * In the Clock app, the abbrevation for the city of Kyiv was changed from KIE to KYI to match the Ukrainian name instead of the Russian name, which is Kiev.