ACTION_GET_CONTENT? Support EXTRA_ALLOW_MULTIPLE, Please

API Level 18 sneaked in a new standard for ACTION_GET_CONTENT that addresses a long-standing request: multiple selections.

ACTION_GET_CONTENT requests can add an EXTRA_ALLOW_MULTIPLE boolean extra. Setting this to true means that the requester would like the user to be able to allow to select multiple pieces of content, not just one.

If you publish an activity with ACTION_GET_CONTENT support, please consider adding support for EXTRA_ALLOW_MULTIPLE. Requesters of ACTION_GET_CONTENT will need to handle the case where the user chooses some activity that lacks EXTRA_ALLOW_MULTIPLE support. However, some developers will not bother trying to ask for EXTRA_ALLOW_MULTIPLE, until there is a decent chance that some activity will actually honor it.