Update the overall db timeout for writing data from a single file during ingestion

- This value is used in the processSingleFile function.
- Internally that function invokes WriteTraces on sqlTraceStore. WriteTraces has configured the timeout to 15 minutes.
- Since the parent context object has a lower timeout than the child context (in WriteTraces), the context was getting cancelled in a minute instead of 15 minutes as expected in WriteTraces.
- This caused the WriteTraces function to timeout in a minute. This impacts writing of large files which is expected to take longer.
- Updating the parent timeout to 15 minutes so that WriteTraces is not cancelled before the expected deadline.

Change-Id: Ia44830d037cfc3afeafece175821b48385633c60
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/932616
Auto-Submit: Ashwin Verleker <ashwinpv@google.com>
Commit-Queue: Ashwin Verleker <ashwinpv@google.com>
Reviewed-by: Farid (Mojtaba) Faridzad <faridzad@google.com>
Commit-Queue: Farid (Mojtaba) Faridzad <faridzad@google.com>

perf/go/ingest/process/process.go

diff --git a/perf/go/ingest/process/process.go b/perf/go/ingest/process/process.go
index b29d3ab..15fa245 100644
--- a/perf/go/ingest/process/process.go
+++ b/perf/go/ingest/process/process.go
@@ -31,7 +31,7 @@
 
 // defaultDatabaseTimeout is the context timeout used when making a request that
 // involves the database. For more complex requests use config.QueryMaxRuntime.
-const defaultDatabaseTimeout = time.Minute
+const defaultDatabaseTimeout = 15 * time.Minute
 
 // sendPubSubEvent sends the unencoded params and paramset found in a single
 // ingested file to the PubSub topic specified in the selected Perf instances