Preventing a shortcut which requires permissions from being added to

A shortcut can be added by any app as INSTALL_SHORTCUT is a normal
level permission. But the intent is actually launched by the launcher
app which can have other permission as well.

> When adding a shortcut from the broadcast, verify that the intent does
not require any permission
> When adding a shortcut using the two-step drop process, verify that
the source app also has the permission to create such a shortcut

Bug: 30778130
Change-Id: I33a391bc0af81248aaff4459aaa79d1adc77926b
(cherry picked from commit fb5096d07bb3bb59fd4b5db6b68613030169b4bd)
(cherry picked from commit 116d34bc634cfe12ffa2f291df286629d5abdcfd)
3 files changed