[release/7.0] Move to an RTM SDK (#44233)

* [release/7.0] Move to an RTM SDK
* Update global.json
* Update global.json
* Grab part of #43802
  - `cherry-pick`ed from d184b978

Co-authored-by: William Godbe <wigodbe@microsoft.com>
Co-authored-by: Brennan <brecon@microsoft.com>

global.json

 {
   "sdk": {
-    "version": "7.0.100-rc.1.22431.12"
+    "version": "7.0.100-rtm.22478.12"
   },
   "tools": {
-    "dotnet": "7.0.100-rc.1.22431.12",
+    "dotnet": "7.0.100-rtm.22478.12",
     "runtimes": {
       "dotnet/x86": [
         "$(MicrosoftNETCoreBrowserDebugHostTransportVersion)"

src/ProjectTemplates/Shared/TemplatePackageInstaller.cs

@@ -139,7 +139,7 @@ internal static class TemplatePackageInstaller
         {
             var proc = await RunDotNetNew(output, $"\"{templateName}\"");
 
-            if (!proc.Error.Contains("No templates found matching:"))
+            if (!proc.Error.Contains("No templates or subcommands found matching:"))
             {
                 throw new InvalidOperationException($"Failed to uninstall previous templates. The template '{templateName}' could still be found.");
             }