Shift the end time forward by a day in the alertGroup api

- Currently it renders the anomalies on the extreme right of the plot.
- This change should get those a bit more towards the center while still showing the data points that led to the regressions.

Bug: b/295957231
Change-Id: I79c70c14850f3bc2da891ca940cd4eef2b8f0fb2
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/747818
Commit-Queue: Ashwin Verleker <ashwinpv@google.com>
Reviewed-by: Eduardo Yap <eduardoyap@google.com>

perf/go/alertgroup/alertgroupdetails.go

diff --git a/perf/go/alertgroup/alertgroupdetails.go b/perf/go/alertgroup/alertgroupdetails.go
index ace3a9f..1e28952 100644
--- a/perf/go/alertgroup/alertgroupdetails.go
+++ b/perf/go/alertgroup/alertgroupdetails.go
@@ -5,6 +5,7 @@
 	"net/url"
 	"strconv"
 	"strings"
+	"time"
 
 	"go.skia.org/infra/go/sklog"
 	"go.skia.org/infra/go/util"
@@ -32,7 +33,11 @@
 		}
 		endCommit, _ := perfGit.CommitFromCommitNumber(ctx, types.CommitNumber(alertGroup.EndCommitNumber))
 		queryUrl["begin"] = []string{strconv.Itoa(int(startCommit.Timestamp))}
-		queryUrl["end"] = []string{strconv.Itoa(int(endCommit.Timestamp))}
+
+		// We will shift the end time by a day so the graph doesn't render the anomalies right at the end
+		endTime := time.Unix(endCommit.Timestamp, 0).AddDate(0, 0, 1)
+
+		queryUrl["end"] = []string{strconv.Itoa(int(endTime.Unix()))}
 	}
 
 	// We do not want duplicate params, hence create maps to use as a set datastructure for each param