First Run Message and LZMA Cache Expansion are intertwined.

Steps to reproduce

1. Download a CLI drop
2. Delete the .lzma archive that comes in the drop.
3. Run dotnet help
4. Run dotnet help

Expected behavior

The first invocation of dotnet help prints the first run message, the second does not.

Actual behavior

Both commands print the first run goop. I think this is because the cache priming does not happen (since the LZMA file is missing) and so we never write the sentinel file (and so stuff in DotnetFirstTimeUseConfigurer thinks it always needs to write messages)

Environment data

dotnet --info output:

[livarcocc]

By the way, these are now separated. The cache expansion sentinel and the first run message sentinel.

[livarcocc]

@ericstj A failure is not blocking. Has never been blocking, however, we will display the message and attempt to prime the cache over and over again until we succeed. The idea of not having an lzma archive present is new and we need to deal/think through it and make the appropriate changes.