[Description] Optional [Boolean] parameter. If true, to determine if a dependency should be copied locally, one of the checks done is to see if the parent reference in the project file has the Private metadata set. If set, then the Private value is used as a dependency. If the metadata is not set, then the dependency goes through the same checks as the parent reference. One of these checks is to see if the reference is in the GAC. If a reference is in the GAC, then it is not copied locally, because it is assumed to be in the GAC on the target machine. This only applies to a specific reference and not its dependencies. For example, a reference in the project file that is in the GAC is not copied locally, but its dependencies are copied locally because they are not in the GAC. If false, project file references are checked to see if they are in the GAC, and are copied locally as appropriate. Dependencies are checked to see if they are in the GAC and are also checked to see if the parent reference from the project file is in the GAC. If the parent reference from the project file is in the GAC, the dependency is not copied locally. Whether this parameter is true or false, if there are multiple parent references and any of them are not in the GAC, then all of them are copied locally. [Parameter] 
CopyLocalDependenciesWhenParentReferenceInGac