introduced packages.include

templates/vsprojects/grpc/packages.config.template

-<?xml version="1.0" encoding="utf-8"?>
-<packages>
-  <package id="openssl" version="1.0.2.1" targetFramework="Native" />
-  <package id="openssl.redist" version="1.0.2.1" targetFramework="Native" />
-  <package id="zlib" version="1.2.8.7" targetFramework="Native" />
-  <package id="zlib.redist" version="1.2.8.7" targetFramework="Native" />
-</packages>
\ No newline at end of file
+<%namespace file="../packages.include" import="gen_packages_config"/>\
+${gen_packages_config(['openssl','zlib'])}
\ No newline at end of file

templates/vsprojects/grpc_csharp_ext/packages.config.template

-<?xml version="1.0" encoding="utf-8"?>
-<packages>
-  <package id="openssl" version="1.0.2.1" targetFramework="Native" />
-  <package id="openssl.redist" version="1.0.2.1" targetFramework="Native" />
-  <package id="zlib" version="1.2.8.7" targetFramework="Native" />
-  <package id="zlib.redist" version="1.2.8.7" targetFramework="Native" />
-</packages>
\ No newline at end of file
+<%namespace file="../packages.include" import="gen_packages_config"/>\
+${gen_packages_config(['openssl','zlib'])}
\ No newline at end of file

templates/vsprojects/grpc_unsecure/packages.config.template

-<?xml version="1.0" encoding="utf-8"?>
-<packages>
-  <package id="zlib" version="1.2.8.7" targetFramework="Native" />
-  <package id="zlib.redist" version="1.2.8.7" targetFramework="Native" />
-</packages>
\ No newline at end of file
+<%namespace file="../packages.include" import="gen_packages_config"/>\
+${gen_packages_config(['zlib'])}
\ No newline at end of file

templates/vsprojects/packages.include

+<%def name="gen_packages_config(packages)">\
+<?xml version="1.0" encoding="utf-8"?>
+<packages>
+  % if 'openssl' in packages:
+  <package id="openssl" version="1.0.2.1" targetFramework="Native" />
+  <package id="openssl.redist" version="1.0.2.1" targetFramework="Native" />
+  % endif
+  % if 'zlib' in packages:
+  <package id="zlib" version="1.2.8.7" targetFramework="Native" />
+  <package id="zlib.redist" version="1.2.8.7" targetFramework="Native" />
+  % endif
+</packages>
+</%def>\
\ No newline at end of file

templates/vsprojects/vcxproj_defs.include

+<%namespace file="packages.include" import="gen_packages_config"/>\
 <%def name="get_repo_root()">..\..</%def>\
 <%def name="to_windows_path(path)">${path.replace('/','\\')}</%def>\
 <%def name="get_subsystem(is_library)">${'Windows' if is_library else 'Console'}</%def>\