device/fido: increase device (and thus caBLE) timeout to 20 seconds.

Windows is commonly observed to take about 10 seconds to establish a
GATT connection to caBLE devices. Some reports, however, are suggesting
that even a 15 second timeout is insufficient. This change raises that
timeout 20 seconds. It's unclear whether humans will actually wait
around this long, at least this might make some caBLE actions
_possible_.

Change-Id: I99a9647cdab8ed7475ce13b1652731a5109c8d28
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1884756
Auto-Submit: Adam Langley <agl@chromium.org>
Commit-Queue: Martin Kreichgauer <martinkr@google.com>
Reviewed-by: Martin Kreichgauer <martinkr@google.com>
Cr-Commit-Position: refs/heads/master@{#710632}

device/fido/fido_constants.cc

@@ -32,7 +32,7 @@ const char kCredentialManagementPreviewMapKey[] = "credentialMgmtPreview";
 const char kBioEnrollmentMapKey[] = "bioEnroll";
 const char kBioEnrollmentPreviewMapKey[] = "userVerificationMgmtPreview";
 
-const base::TimeDelta kDeviceTimeout = base::TimeDelta::FromSeconds(15);
+const base::TimeDelta kDeviceTimeout = base::TimeDelta::FromSeconds(20);
 const base::TimeDelta kU2fRetryDelay = base::TimeDelta::FromMilliseconds(200);
 
 const char kFormatKey[] = "fmt";