profiler: add function for checking if filename is in profile
profiler: add function for checking if filename is in profile

Change-Id: I6eedaf12255fe1b7bcfa7859521aa960781fe5ab
Reviewed-on: https://code-review.googlesource.com/c/35752
Reviewed-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>
Reviewed-by: Alexey Alexandrov <707c85aa1ca9cc766e4957d3fb95a91b4e895454@google.com>

googleapis/google-cloud-go,googleapis/google-cloud-go,googleapis/google-cloud-go,googleapis/google-cloud-go