Add activities to handle external storage intents

Adds 2 activities with the appropriate intent-filters to handle intents
used to control OP_MANAGE_EXTERNAL_STORAGE:
* Generic activity to handle ACTION_MANAGE_ALL_FILES_ACCESS_PERMISSION
  which control all apps (that request MANAGE_EXTERNAL_STORAGE).
* App specific activity to handle
  ACTION_MANAGE_APP_ALL_FILES_ACCESS_PERMISSION. The intent filter
  expects the name of the package as data in the intent.

Test: manual
Bug: 146425146
Change-Id: Iebc7d153eac6ffe0b9bd75196bc8ecf9cb687939