I was able to figure it out.
Create the following file: C:\ProjectName\ProjectName\nsight_tegra_build_overrides.xml
<?xml version="1.0" encoding="utf-8"?>
<project name="ProjectName" Basedir="C:\ProjectName\ProjectName\">
<property name="android.library.reference.1" value = "../../NVPACK/android-sdk-windows/extras/android/support/v7/appcompat" />
</project>
The overrides file adds this line to nsight_tegra_build.xml when it is generated. The path for android.library.reference.1 must be a relative path. See How to define v7 appcompat dependency correctly?. Run:
c:\NVPACK\apache-ant-1.8.2\bin>android update project -p c:\NVPACK\android-sdk-windows\extras\android\support\v7\appcompat\
Change target=android-19
to target=android-21
in C:\NVPACK\android-sdk-windows\extras\android\support\v7\appcompat\project.properties. After that, it should be buildable from within Visual Studio.