Revert "Implement a global maximum on number of shortcuts an app can publish"

This reverts commit fa4b2dc6.

Reason for revert: bugs related to conversation shortcuts can lead to system retaining shortcuts exceeding this number, causing crashes in chat apps such as whatsapp, messages ... e.t.c

Change-Id: If485dc29e4f906d2ce5ec6836b3c4c47b5f21e23