This method will be called to report the result of the package
installation attempt.
param
basePackageName Name of the package whose installation was
attempted
param
extras If non-null, this Bundle contains extras providing
additional information about an install failure. See
{@link android.content.pm.PackageManager} for documentation
about which extras apply to various failures; in particular
the strings named EXTRA_FAILURE_*.
param
returnCode The numeric success or failure code indicating the
basic outcome