tools/heap_profile: Fix for Windows
tools/heap_profile: Fix for Windows

Skip gzipping on Windows. Also improve final messages.

Bug: https://github.com/google/perfetto/issues/133
Test: manual on Windows 10
Change-Id: I59453c8e2cd8cde886eb495cde0aa044c2188150
google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto