change virustotal flag to -V

[r-tx]

for the download-apks command -v is defined as shorthand for both --virustotal and --verbose.

Suggesting to change --virustotal to use -V (upper v) for short.

[roaree]

Nice spot! This seems like a backwards compatible change too - running main on my machine, passing -v currently sets verbose=True and virustotal=False.

Will leave open a day or two in case folks have other thoughts