flutter-ics-homescreen: bump SRCREV

flutter-ics-homescreen: bump SRCREV

Update SRCREV to pick up:

6188a4c Add support for CI screenshot testing
60f0492 Add gitreview file for Royal Ricefish branch
f957ceb Add gitlab issue/merge request templates

Bug-AGL: SPEC-5203

Change-Id: I7820f8831ec76d7a1c8d424d211130b92cc66762
Signed-off-by: Scott Murray <scott.murray@konsulko.com>
Reviewed-on: https://gerrit.automotivelinux.org/gerrit/c/AGL/meta-agl-demo/+/30179
ci-image-build: Jenkins Job builder account
ci-image-boot-test: Jenkins Job builder account
Reviewed-by: Naoto YAMAGUCHI <naoto.yamaguchi@aisin.co.jp>
Tested-by: Jenkins Job builder account