Add prompt to customize name of saved trace in perfetto UI
Add prompt to customize name of saved trace in perfetto UI

Earlier, the trace was downloaded with a generic name and it was not
customizable. Added a prompt similar to chrome://tracing to customize
name of saved trace.

Bug: 204852322
Change-Id: I745923ba8358c753f6260ef8e447591476b4add6
google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto