Use DotNetBuildSourceOnly unified build control instead of DotNetBuildFromSource

Author: akoeplinger

Directory.Build.props

@@ -5,6 +5,6 @@
 
   <PropertyGroup>
     <!-- we're not building all of llvm for now in source build, just jittools -->
-    <BuildJitToolsOnly Condition="'$(BuildJitToolsOnly)' == '' and '$(DotNetBuildFromSource)' == 'true'">true</BuildJitToolsOnly>
+    <BuildJitToolsOnly Condition="'$(BuildJitToolsOnly)' == '' and '$(DotNetBuildSourceOnly)' == 'true'">true</BuildJitToolsOnly>
   </PropertyGroup>
 </Project>

nuget/builds.targets

@@ -5,8 +5,8 @@
 
     <!-- Used to determine if we should build some packages only once across multiple official build legs.
          For offline builds we still set OfficialBuildId but we need to build all the packages for a single
-         leg only, so we also take DotNetBuildFromSource into account. -->
-    <BuildingAnOfficialBuildLeg Condition="'$(OfficialBuildId)' != '' AND '$(DotNetBuildFromSource)' != 'true'">true</BuildingAnOfficialBuildLeg>
+         leg only, so we also take DotNetBuildSourceOnly into account. -->
+    <BuildingAnOfficialBuildLeg Condition="'$(OfficialBuildId)' != '' AND '$(DotNetBuildSourceOnly)' != 'true'">true</BuildingAnOfficialBuildLeg>
 
     <!-- During an official build, only build identity packages on windows x64 legs -->
     <BuildIdentityPackage Condition="'$(BuildingAnOfficialBuildLeg)' == 'true' AND ('$(OS)' != 'Windows_NT' OR '$(BuildArch)' != 'x64')">false</BuildIdentityPackage>