Sending MY_PACKAGE_SUSPENDED to suspended apps

Added new broadcast actions MY_PACKAGE_SUSPENDED and
MY_PACKAGE_UNSUSPENDED, which are sent to the package that is affected
by the suspend state change. A suspended package also receives a bundle
of app extras to pass more information. This makes it easier for
packages to deal with being suspended/unsuspended.

Also updated some existing documentation to make it clearer.

Test: atest com.android.server.pm.SuspendPackagesTest

Bug: 75036698
Change-Id: I772cf0c023669bc946e07ced4ebccfa74f6835b2