sharing observation containing attachment does not work on Android 12+

[achou11]

pressing the Share button on the observation screen does not do anything when the observation contains an attachment. in development, doing so surfaces the following error message:

Targeting S+ (version 31 and above) requires that one of FLAG_IMMUTABLE or FLAG_MUTABLE be specified when creating a PendingIntent.
Strongly consider using FLAG_IMMUTABLE, only use FLAG_MUTABLE if some functionality depends on the PendingIntent being mutable, e.g. if it needs to be used with inline replies or bubbles.",

see react-native-share/react-native-share#1073 for reporting of issue in react-native-share