Use PackageManager.INSTALL_XXX error codes (15/n)

2 sets of error codes are a source of confusion. This CL migrates
all uses of SessionInfo.SESSION_XXX error codes to
PackageManager.INSTALL_XXX ones which provide a richer set of
error codes.

Bug: 210359798
Test: atest StagingManagerTest \
            com.android.server.pm.test.PackageInstallerSessionTest \
	    CtsStagedInstallHostTestCases

Change-Id: I0a721a48293029983ffd80912adbb2229ab4ee5d