tp: improve query constraint debug strings
tp: improve query constraint debug strings

This massively improves the usability of -d mode of
trace_processor_shell.

Bug: 220373202
Change-Id: I1c3ab9fe744e891a00534161b8bd6315dc35aa96
google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto