Make system text json version compatible with powershell (#3569)

* Update compiled system text json version for netstandard2.0 and net472 to 6.0.11 for powershell compatibility and add overrides.targets file.

Author: peterrsongg

sdk/src/Core/AWSSDK.Core.NetFramework.csproj

@@ -71,6 +71,11 @@
   <ItemGroup>
     <PackageReference Include="System.Buffers" Version="4.5.1" />
     <PackageReference Include="System.Memory" Version="4.5.5" />
-    <PackageReference Include="System.Text.Json" Version="8.0.5" />
+  <!-- Powershell (pwsh) will have a preloaded version of System.Text.Json that is older than
+  the version we will ship in core nuget packages and dlls, so we compile with an  older version of STJ
+  but ship nuget packages and dlls with newer versions of STJ. If we don't do this then sdk assemblies will fail
+  to load in powershell due to unsupported versions -->
+    <PackageReference Include="System.Text.Json" Version="6.0.11" />
   </ItemGroup>
+  <Import Project="overrides.targets"/>
 </Project>

sdk/src/Core/AWSSDK.Core.NetStandard.csproj

@@ -83,6 +83,10 @@
     <PackageReference Include="Microsoft.Bcl.AsyncInterfaces" Version="8.0.0" />
     <PackageReference Include="System.Buffers" Version="4.5.1" />
     <PackageReference Include="System.Memory" Version="4.5.5" />
-    <PackageReference Include="System.Text.Json" Version="8.0.5" />
+    <!-- Powershell 7+ already has a preloaded version of system text json which is older than the version 
+    we ship in nuget packages and dlls. To ensure SDK assemblies can be loaded in powershell, we must compile with 
+    an older version of System.Text.Json.  -->
+    <PackageReference Include="System.Text.Json" Version="6.0.11" />
   </ItemGroup>
+    <Import Project="overrides.targets"/>
 </Project>

sdk/src/Core/overrides.targets

@@ -0,0 +1,6 @@
+<Project>
+  <ItemGroup>
+    <!--The package reference element is dynamically uncommented during the build system ZIP file creation-->
+    <!--<PackageReference Update="System.Text.Json" Version="8.0.5" />-->
+  </ItemGroup>
+</Project>