Send the intent after verification completed (6/n)

This will remove the need for listening to ACTION_SESSION_UPDATED events.

Note this will break CTS which always assumes a successful intent to be
recevied after calling Session#commit() for a staged session. We will fix
that in the next CL.

PackageManagerShellCommand is also modified to make --staged-ready-timeout
continue to work as before.

Bug: 210359798
Test: atest GtsStagedInstallHostTestCases \
            CtsStagedInstallHostTestCases \
	    StagedInstallInternalTest

Change-Id: I4d6d3bcf45f0215d2b5e5bd079f8919a0fccbca4