flutter-dashboard: update SRCREV

flutter-dashboard: update SRCREV

Update SRCREV to pick up:

2fbe5f8 VSS 4.0 updates
f7d640c Revert "flutter-dashboard: fix pixel overflow"
d5f5334 flutter-dashboard: fix pixel overflow

Bug-AGL: SPEC-4970

Change-Id: Iaf1ba13bf98e5c049ac6d14121108d6666cc12a2
Signed-off-by: Scott Murray <scott.murray@konsulko.com>
Reviewed-on: https://gerrit.automotivelinux.org/gerrit/c/AGL/meta-agl-demo/+/29529
Reviewed-by: Jan-Simon Moeller <jsmoeller@linuxfoundation.org>
ci-image-build: Jenkins Job builder account
ci-image-boot-test: Jenkins Job builder account
Tested-by: Jenkins Job builder account