[C#] TimestampArray conversion logic for nano and micro is wrong

[asfimport]

The logic in this line looks wrong

case TimeUnit.Microsecond:
    return ticks / TimeSpan.TicksPerMillisecond / 1000;

It should read

case TimeUnit.Microsecond:
    return (ticks / TimeSpan.TicksPerMillisecond) * 1000;

Reporter: Xavier Lacroze / @0x0L
Assignee: Xavier Lacroze / @0x0L

PRs and other links:

• GitHub Pull Request #10561

_{Note: This issue was originally created as ARROW-13128. Please see the migration documentation for further details.}

[asfimport]

Eric Erhardt / @eerhardt:
Issue resolved by pull request 10561
#10561