Sut planner update, removes ref attributes

[igivon]

when adding sut a "virtual so" with ref attribute. if sut is updated with the sut planner the ref attribute will be deleted.
For Example:

1. create sut (with <DesktopApplicationSystemObjectMain ref="md/DesktopApplicationSystemObjectMain"/>) :

<md>
    <class>com.cellebrite.automation.MdMainSo</class>
    <DesktopApplicationSystemObjectMain>
        <class>xxxxxxxxxxxxxx</class>
        <desktopWindowsTitle>xxxxxxxxxxxx</desktopWindowsTitle>
        <desktopApplicationFullPat>xxxxxxxxxxxxx</desktopApplicationFullPath>
        <waitApplicationLoading>15</waitApplicationLoading>
        <loadAppAtSoInit>false</loadAppAtSoInit>
    </DesktopApplicationSystemObjectMain>
</md>
<DesktopApplicationSystemObjectMain **ref="md/DesktopApplicationSystemObjectMain**"/>

2. update any field at sut planner and save 3. enter the sut again with notepad and see ref attribute is gone

[itaiag]

SUT planner does not support XML references at this stage.