A Bundle forming a mapping of potential target package names to different extras Bundles to add to the default intent extras in Intent.ExtraIntent when used with Intent.ActionChooser. Each key should be a package name. The package need not be currently installed on the device.

An application may choose to provide alternate extras for the case where a user selects an activity from a predetermined set of target packages. If the activity the user selects from the chooser belongs to a package with its package name as a key in this bundle, the corresponding extras for that package will be merged with the extras already present in the intent at Intent.ExtraIntent. If a replacement extra has the same key as an extra already present in the intent it will overwrite the extra from the intent.

Examples:

• An application may offer different Intent.ExtraText to an application when sharing with it via Intent.ActionSend, augmenting a link with additional query parameters for that target.
• An application may offer additional metadata for known targets of a given intent to pass along information only relevant to that target such as account or content identifiers already known to that application.

[Android Documentation]